American Civil War Part I

The American Civil War was a civil war in the United States fought from 1861 to 1865. The Union faced secessionists in eleven Southern states grouped together as the Confederate States of America. The Union won the war, which remains the bloodiest in U.S. history.

Among the 34 U.S. states in January 1861, seven Southern slave states individually declared their secession from the U.S. and formed the Confederate States of America. War broke out in April 1861 when they attacked a U.S. fortress, Fort Sumter. The Confederacy grew to include eleven states; it claimed two more states and several western territories. The Confederacy was never diplomatically recognized by any foreign country. The states that remained loyal including Border States where slavery was legal were known as the Union or the North. The war ended with the surrender of all the Confederate armies and the collapse of Confederate government in spring 1865.

The war had its origin in the factious issue of slavery, especially the extension of slavery into the western territories. Four years of intense combat left 620,000 to 750,000 soldiers dead, a higher number than the American military deaths of World War I and World War II combined, and destroyed much of the South's infrastructure. The Confederacy collapsed and slavery was abolished in the entire country. The Reconstruction Era (1863–1877) overlapped and followed the war, with its fitful process of restoring national unity, strengthening the national government, and granting civil rights to the freed slaves.

History

In the 1860 presidential election, Republicans, led by Abraham Lincoln, supported banning slavery in all the U.S. territories, something the Southern states viewed as a violation of their constitutional rights and as being part of a plan to eventually abolish slavery. The Republican Party, dominant in the North, secured a majority of the electoral votes, and Lincoln was elected the first Republican president, but before his inauguration, seven slave states with cotton-based economies formed the Confederacy. The first six to secede had the highest proportions of slaves in their populations, a total of 48.8 percent. Eight remaining slave states continued to reject calls for secession. Outgoing Democratic President James Buchanan and the incoming Republicans rejected secession as illegal. Lincoln’s March 4, 1861 inaugural address declared his administration would not initiate civil war. Speaking directly to "the Southern States," he reaffirmed, "I have no purpose, directly or indirectly to interfere with the institution of slavery in the United States where it exists. I believe I have no lawful right to do so, and I have no inclination to do so."^[   After Confederate forces seized numerous federal forts within territory claimed by the Confederacy, efforts at compromise failed and both sides prepared for war. The Confederates assumed that European countries were so dependent on "King Cotton" that they would intervene, but none did, and none recognized the new Confederate States of America.

Hostilities began on April 12, 1861, when Confederate forces fired upon Fort Sumter.  While in the Western Theater the Union made significant permanent gains, in the Eastern Theater, battle was inconclusive in 1861–62. The autumn 1862 Confederate campaigns into Maryland and Kentucky failed, dissuading British intervention; Lincoln issued the Emancipation Proclamation, which made ending slavery a war goal.  To the west, by summer 1862 the Union destroyed the Confederate river navy, then much of their western armies, and seized New Orleans. The 1863 Union siege of Vicksburg split the Confederacy in two at the Mississippi River. In 1863, Robert E. Lee's Confederate incursion north ended at the Battle of Gettysburg. Western successes led to Ulysses S. Grant's command of all Union armies in 1864. Inflicting an ever-tightening naval blockade of Confederate ports, the Union marshaled the resources and manpower to attack the Confederacy from all directions, leading to the fall of Atlanta to William T. Sherman and his march to the sea. The last significant battles raged around the Siege of Petersburg. Lee's escape attempt ended with his surrender at Appomattox Court House, on April 9, 1865. While the military war was coming to an end, the political reintegration of the nation was to take another 12 years of the Reconstruction Era.

The American Civil War was one of the earliest true industrial wars. Railroads, the telegraph, steamships, and mass-produced weapons were employed extensively. The mobilization of civilian factories, mines, shipyards, banks, transportation and food supplies all foreshadowed the impact of industrialization in World War I.  It remains the deadliest war in American history. From 1861 to 1865, it has been traditionally estimated that about 620,000 died but recent scholarship argues that 750,000 soldiers died, along with an undetermined number of civilians.  By one estimate, the war claimed the lives of 10 percent of all Northern males 20–45 years old, and 30 percent of all Southern white males aged 18–40.

Causes of secession

The causes of the Civil War were complex and have been controversial since the war began. James C. Bradford wrote that the issue has been further complicated by historical revisionists, who have tried to offer a variety of reasons for the war.  Slavery was the central source of escalating political tension in the 1850s. The Republican Party was determined to prevent any spread of slavery, and many Southern leaders had threatened secession if the Republican candidate, Lincoln, won the 1860 election. After Lincoln won without carrying a single Southern state, many Southern whites felt that disunion had become their only option, because they thought that they were losing representation, which would hamper their ability to promote pro-slavery acts and policies.

Root causes

Status of the states, 1861.

   States that seceded before April 15, 1861

   States that seceded after April 15, 1861

   Union states that permitted slavery

   Union states that banned slavery

   Territories

Slavery

Contemporary actors, the Union and Confederate leadership and fighting soldiers on both sides believed that slavery caused the Civil War. Union men mainly believed the war was to emancipate the slaves. Confederates fought to protect southern society, and slavery as an integral part of it.  From the anti-slavery perspective, the issue was primarily about whether the system of slavery was an anachronistic evil that was incompatible with Republicanism in the United States.  The strategy of the anti-slavery forces was containment — to stop the expansion and thus put slavery on a path to gradual extinction.  The slave-holding interests in the South denounced this strategy as infringing upon their Constitutional rights.  Southern whites believed that the emancipation of slaves would destroy the South's economy because of the alleged laziness of blacks under free labor.

Slavery was illegal in the North, having been outlawed in the late 18th and early 19th century. It was fading in the border states and in Southern cities, but was expanding in the highly profitable cotton districts of the South and Southwest. Subsequent writers on the American Civil War looked to several factors explaining the geographic divide, including sectionalism, protectionism, and state's rights.

Sectionalism

Sectionalism refers to the different economies, social structure, customs and political values of the North and South.  It increased steadily between 1800 and 1860 as the North, which phased slavery out of existence, industrialized, urbanized, and built prosperous farms, while the Deep South concentrated on plantation agriculture based on slave labor, together with subsistence farming for poor freedmen. In the 1840s and 50s, the issue of accepting slavery (in the guise of rejecting slave-owning bishops and missionaries) split the nation's largest religious denominations (the Methodist, Baptist and Presbyterian churches) into separate Northern and Southern denominations.

Historians have debated whether economic differences between the industrial Northeast and the agricultural South helped cause the war. Most historians now disagree with the economic determinism of historian Charles A. Beard in the 1920s and emphasize that Northern and Southern economies were largely complementary. While socially different, the sections economically benefited each other.

Protectionism

Historically, southern slave-holding states, because of their low cost manual labor, had little perceived need for mechanization, and supported having the right to sell cotton and purchase manufactured goods from any nation. Northern states, which had heavily invested in their still-nascent manufacturing, could not compete with the full-fledged industries of Europe in offering high cotton prices imported from the South and low prices for manufactured exports in return. Thus, northern manufacturing interests supported tariffs and protectionism while southern planters demanded free trade.

The Democrats in Congress, controlled by Southerners, wrote the tariff laws in the 1830s, 1840s, and 1850s, and kept reducing rates so that the 1857 rates were the lowest since 1816. The Whigs and Republicans complained because they favored high tariffs to stimulate industrial growth, and Republicans called for an increase in tariffs in the 1860 election. The increases were only enacted in 1861 after Southerners resigned their seats in Congress.  The tariff issue was and is sometimes cited–long after the war–by Lost Cause historians and neo-Confederate apologists. In 1860–61 none of the groups that proposed compromises to head off secession raised the tariff issue.  Pamphleteers north and south rarely mentioned the tariff, and when some did, for instance, Matthew Fontaine Maury and John Lothrop Motley, they were generally writing for a foreign audience.

States' rights

The South argued that each state had the right to secede–leave the Union–at any time, and that the Constitution was a "compact" or agreement among the states. Northerners (including President Buchanan) rejected that notion as opposed to the will of the Founding Fathers who said they were setting up a perpetual union.  Historian James McPherson writes concerning states' rights and other non-slavery explanations:

While one or more of these interpretations remain popular among the Sons of Confederate Veterans and other Southern heritage groups, few professional historians now subscribe to them. Of all these interpretations, the states'-rights argument is perhaps the weakest. It fails to ask the question, states' rights for what purpose? States’ rights, or sovereignty, were always more a means than an end, an instrument to achieve a certain goal more than a principle.

Territorial crisis

Between 1803 and 1854, the United States achieved a vast expansion of territory through purchase, negotiation, and conquest. At first, the new states carved out of these territories entering the union were apportioned equally between slave and free states. It was over territories west of the Mississippi that the proslavery and antislavery forces collided.

With the conquest of northern Mexico west to California in 1848, slaveholding interests looked forward to expanding into these lands and perhaps Cuba and Central America as well.  Northern "free soil" interests vigorously sought to curtail any further expansion of slave territory. The Compromise of 1850 over California balanced a free-soil state with stronger fugitive slave laws for a political settlement after four years of strife in the 1840s. But the states admitted following California were all free: Minnesota (1858), Oregon (1859) and Kansas (1861). In the southern states the question of the territorial expansion of slavery westward again became explosive.  Both the South and the North drew the same conclusion: "The power to decide the question of slavery for the territories was the power to determine the future of slavery itself."

By 1860, four doctrines had emerged to answer the question of federal control in the territories, and they all claimed they were sanctioned by the Constitution, implicitly or explicitly.  The first of these "conservative" theories, represented by the Constitutional Union Party, argued that the Missouri Compromise apportionment of territory north for free soil and south for slavery should become a Constitutional mandate. The Crittenden Compromise of 1860 was an expression of this view.

The second doctrine of Congressional preeminence, championed by Abraham Lincoln and the Republican Party, insisted that the Constitution did not bind legislators to a policy of balance – that slavery could be excluded in a territory as it was done in the Northwest Ordinance of 1787 at the discretion of Congress, thus Congress could restrict human bondage, but never establish it. The Wilmot Proviso announced this position in 1846.

Senator Stephen A. Douglas proclaimed the doctrine of territorial or "popular" sovereignty – which asserted that the settlers in a territory had the same rights as states in the Union to establish or disestablish slavery as a purely local matter.  The Kansas-Nebraska Act of 1854 legislated this doctrine.  In Kansas Territory, years of pro and anti-slavery violence and political conflict erupted; the congressional House of Representatives voted to admit Kansas as a free state in early 1860, but its admission in the Senate was delayed until January 1861, after the 1860 elections when southern senators began to leave.^[

The fourth theory was advocated by Mississippi Senator Jefferson Davis, one of state sovereignty ("states' rights"), also known as the "Calhoun doctrine", named after the South Carolinian political theorist and statesman John C. Calhoun Rejecting the arguments for federal authority or self-government, state sovereignty would empower states to promote the expansion of slavery as part of the Federal Union under the U.S. Constitution.  "States' rights" was an ideology formulated and applied as a means of advancing slave state interests through federal authority.  As historian Thomas L. Krannawitter points out, the "Southern demand for federal slave protection represented a demand for an unprecedented expansion of federal power."  These four doctrines comprised the major ideologies presented to the American public on the matters of slavery, the territories and the U.S. Constitution prior to the 1860 presidential election.

National elections

Beginning in the American Revolution and accelerating after the War of 1812, the people of the United States grew in their sense of country as an important example to the world of a national republic of political liberty and personal rights. Previous regional independence movements such as the Greek revolt in the Ottoman Empire, division and re-division in the Latin American political map, and the British-French Crimean triumph leading to an interest in redrawing Europe along cultural differences, all conspired to make for a time of upheaval and uncertainty about the basis of the nation-state. In the world of 19th century self-made Americans, growing in prosperity, population and expanding westward, "freedom" could mean personal liberty or property rights. The unresolved difference would cause failure—first in their political institutions, then in their civil life together.

Nationalism and honor

Nationalism was a powerful force in the early 19th century, with famous spokesmen such as Andrew Jackson and Daniel Webster. While practically all Northerners supported the Union, Southerners were split between those loyal to the entire United States (called "unionists") and those loyal primarily to the southern region and then the Confederacy.  C. Vann Woodward said of the latter group,

A great slave society ... had grown up and miraculously flourished in the heart of a thoroughly bourgeois and partly puritanical republic. It had renounced its bourgeois origins and elaborated and painfully rationalized its institutional, legal, metaphysical, and religious defenses ... When the crisis came it chose to fight. It proved to be the death struggle of a society, which went down in ruins.

Perceived insults to Southern collective honor included the enormous popularity of Uncle Tom’s Cabin (1852) and the actions of abolitionist John Brown in trying to incite a slave rebellion in 1859.

While the South moved toward a Southern nationalism, leaders in the North were also becoming more nationally minded, and rejected any notion of splitting the Union. The Republican national electoral platform of 1860 warned that Republicans regarded disunion as treason and would not tolerate it: "We denounce those threats of disunion ... as denying the vital principles of a free government and as an avowal of contemplated treason, which it is the imperative duty of an indignant people sternly to rebuke and forever silence." The South ignored the warnings: Southerners did not realize how ardently the North would fight to hold the Union together.

Lincoln's election

The election of Abraham Lincoln in November 1860 was the final trigger for secession.  Efforts at compromise, including the "Corwin Amendment" and the "Crittenden Compromise", failed. Southern leaders feared that Lincoln would stop the expansion of slavery and put it on a course toward extinction. The slave states, which had already become a minority in the House of Representatives, were now facing a future as a perpetual minority in the Senate and Electoral College against an increasingly powerful North. Before Lincoln took office in March 1861, seven slave states had declared their secession and joined to form the Confederacy.

Outbreak of the war

Secession crisis

The election of Lincoln caused the legislature of South Carolina to call a state convention to consider secession. Prior to the war, South Carolina did more than any other Southern state to advance the notion that a state had the right to nullify federal laws and, even, secede from the United States. The convention unanimously voted to secede on December 20, 1860 and adopted the "Declaration of the Immediate Causes Which Induce and Justify the Secession of South Carolina from the Federal Union”.  It argued for states' rights for slave owners in the South, but contained a complaint about states' rights in the North in the form of opposition to the Fugitive Slave Act, claiming that Northern states were not fulfilling their federal obligations under the Constitution. The "cotton states" of Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas followed suit, seceding in January and February 1861.

Among the ordinances of secession passed by the individual states, those of three – Texas, Alabama, and Virginia – specifically mentioned the plight of the 'slaveholding states' at the hands of northern abolitionists. The rest make no mention of the slavery issue and are often brief announcements of the dissolution of ties by the legislatures.  However, at least four states – South Carolina, Mississippi, Georgia, and Texas – also passed lengthy and detailed explanations of their causes for secession, all of which laid the blame squarely on the movement to abolish slavery and that movement's influence over the politics of the northern states. The southern states believed slaveholding was a constitutional right because of the Fugitive slave clause of the Constitution.

These states agreed to form a new federal government, the Confederate States of America, on February 4, 1861.  They took control of federal forts and other properties within their boundaries with little resistance from outgoing President James Buchanan, whose term ended on March 4, 1861. Buchanan said that the Dred Scott decision was proof that the South had no reason for secession and that the Union "... was intended to be perpetual," but that, "The power by force of arms to compel a State to remain in the Union," was not among the "... enumerated powers granted to Congress."  One quarter of the U.S. Army – the entire garrison in Texas – was surrendered in February 1861 to state forces by its commanding general, David E. Twigg, who then joined the Confederacy.

As Southerners resigned their seats in the Senate and the House, Republicans were able to pass bills for projects that had been blocked by Southern Senators before the war, including the Morill Tariff, land grant colleges (the Morill Act), a Homestead Act, a transcontinental railroad (the Pacific Railway Act), the National Banking Act and the authorization of United States Notes by the Legal Tender Act of 1862. The Revenue Act of 1861 introduced the income tax to help finance the war.

On December 18, 1860, the Crittenden Compromise was proposed to re-establish the Missouri Compromise line by constitutionally banning slavery in territories to the north of the line while guaranteeing it to the south. The adoption of this compromise likely would have prevented the secession of every southern state apart from South Carolina, but Lincoln and the Republicans rejected it.  It was then proposed to hold a national referendum on the compromise. The Republicans again rejected the idea, although a majority of both Northerners and Southerners would have voted in favor of it.  A pre-war February Peace Conference of 1861met in Washington, proposing a solution similar to that of the Crittenden compromise, it was rejected by Congress. The Republicans proposed an alternative compromise to not interfere with slavery where it existed but the South regarded it as insufficient. Nonetheless, the remaining eight slave states rejected pleas to join the Confederacy following a two-to-one no-vote in Virginia's First Secessionist Convention on April 4, 1861.

On March 4, 1861, Abraham Lincoln was sworn in as President. In his inaugural address, he argued that the Constitution was a more perfect union than the earlier Articles of Confederation and Perpetual Union, that it was a binding contract, and called any secession "legally void".  He had no intent to invade Southern states, nor did he intend to end slavery where it existed, but said that he would use force to maintain possession of Federal property. The government would make no move to recover post offices, and if resisted, mail delivery would end at state lines. Where popular conditions did not allow peaceful enforcement of Federal law, U.S. Marshals and Judges would be withdrawn. No mention was made of bullion lost from U.S. mints in Louisiana, Georgia and North Carolina. In Lincoln's inaugural address, he stated that it would be U.S. policy to only collect import duties at its ports; there could be no serious injury to the South to justify armed revolution during his administration. His speech closed with a plea for the restoration of the bonds of union, famously calling on "the mystic chords of memory" binding the two regions.

The South sent delegations to Washington and offered to pay for the federal properties and enter into a peace treaty with the United States. Lincoln rejected any negotiations with Confederate agents because he claimed the Confederacy was not a legitimate government, and that making any treaty with it would be tantamount to recognition of it as a sovereign government.  Secretary of State William Seward, who at that time saw himself as the real governor or "prime minister" behind the throne of the inexperienced Lincoln, engaged in unauthorized and indirect negotiations that failed.  President Lincoln was determined to hold all remaining Union-occupied forts in the Confederacy, Fort Monroe in Virginia, in Florida, Fort Pickens, Fort Jefferson, and Fort Taylor, and in the cockpit of secession, Charleston, South Carolina's Fort Sumter.

Battle of Fort Sumter

Fort Sumter was located in the middle of the harbor of Charleston, South Carolina, where the U.S. fort's garrison had withdrawn to avoid incidents with local militias in the streets of the city. Unlike Buchanan, who allowed commanders to relinquish possession to avoid bloodshed, Lincoln required Maj. Anderson to hold on until fired upon. Jefferson Davis ordered the surrender of the fort. Anderson gave a conditional reply that the Confederate government rejected, and Davis ordered P.G. T. Beauregard to attack the fort before a relief expedition could arrive. Troops under Beauregard bombarded Fort Sumter on April 12–13, forcing its capitulation.

The attack on Fort Sumter rallied the North to the defense of American nationalism. Historian Allan Nevins says:

The thunderclap of Sumter produced a startling crystallization of Northern sentiment. ... Anger swept the land. From every side came news of mass meetings, speeches, resolutions, tenders of business support, the muster of companies and regiments, the determined action of governors and legislatures."

However, much of the North's attitude was based on the false belief that only a minority of Southerners were actually in favor of secession and that there were large numbers of southern Unionists that could be counted on. Had Northerners realized that most Southerners really did favor secession, they might have hesitated at attempting the enormous task of conquering a united South.

Lincoln called on all the states to send forces to recapture the fort and other federal properties. He cited presidential powers given by the Militia Acts of 1792. With the scale of the rebellion apparently small so far, Lincoln called for only 75,000 volunteers for 90 days.  The governor of Massachusetts had state regiments on trains headed south the next day. In western Missouri, local secessionists seized Liberty Arsenal On May 3, 1861; Lincoln called for an additional 42,000 volunteers for a period of three years.

Four states in the middle and upper South had repeatedly rejected Confederate overtures, but now Virginia, Tennessee, Arkansas, and North Carolina refused to send forces against their neighbors, declared their secession, and joined the Confederacy. To reward Virginia, the Confederate capital was moved to Richmond.

Attitude of the Border States

Maryland, Delaware, Missouri, and Kentucky were slave states that were opposed to both secession and coercing the South. They were later joined by West Virginia, which separated from Virginia and became a new state.

Maryland had numerous anti-Lincoln officials who tolerated anti-army rioting in Baltimore and the burning of bridges, both aimed at hindering the passage of troops to the South. Maryland's legislature voted to stay in the Union, but also rejected hostilities with the South, voting to close Maryland's rail lines to prevent them from being used for war.  Lincoln responded by establishing martial law, and unilaterally suspending habeas corpus, in Maryland, along with sending in militia units from the North.  Lincoln rapidly took control of Maryland and the District of Columbia, by seizing many prominent figures, including arresting 1/3 of the members of the Maryland General Assembly on the day it reconvened.  All were held without trial, ignoring a ruling by the Chief Justice of the U.S. Supreme Court Roger Taney, a Maryland native, that only Congress (and not the president) could suspend habeas corpus (Ex Parte Merriman). Indeed, federal troops imprisoned a prominent Baltimore newspaper editor, Frank Key Howard, Francis Scott Key's grandson, after he criticized Lincoln in an editorial for ignoring the Supreme Court Chief Justice's ruling.

In Missouri, an elected convention on secession voted decisively to remain within the Union. When pro-Confederate Governor Claiborne F. Jackson called out the state militia, it was attacked by federal forces under General Nathaniel Lyon, who chased the governor and the rest of the State Guard to the southwestern corner of the state. (See also: Missouri secession). In the resulting vacuum, the convention on secession reconvened and took power as the Unionist provisional government of Missouri.

Kentucky did not secede; for a time, it declared itself neutral. When Confederate forces entered the state in September 1861, neutrality ended and the state reaffirmed its Union status, while trying to maintain slavery. During a brief invasion by Confederate forces, Confederate sympathizers organized a secession convention, inaugurated a governor, and gained recognition from the Confederacy. The rebel government soon went into exile and never controlled Kentucky.

After Virginia's secession, a Unionist government in Wheeling asked 48 counties to vote on an ordinance to create a new state on October 24, 1861. A voter turnout of 34 percent approved the statehood bill (96 percent approving).  The inclusion of 24 secessionist counties in the state and the ensuing guerrilla war engaged about 40,000 Federal troops for much of the war.  Congress admitted West Virginia to the Union on June 20, 1863. West Virginia provided about 20,000–22,000 soldiers to both the Confederacy and the Union.

A Unionist secession attempt occurred in East Tennessee, but was suppressed by the Confederacy, which arrested over 3,000 men suspected of being loyal to the Union. They were held without trial.

War

The Civil War was a contest marked by the ferocity and frequency of battle. Over four years, 237 named battles were fought, as were many more minor actions and skirmishes, which were often characterized by their bitter intensity and high casualties. In his book The American Civil War, John Keegan writes that "The American Civil War was to prove one of the most ferocious wars ever fought". Without geographic objectives, the only target for each side was the enemy's soldier.

Mobilization

As the first seven states began organizing a Confederacy in Montgomery, the entire U.S. army numbered 16,000. However, Northern governors had begun to mobilize their militias.  The Confederate Congress authorized the new nation up to 100,000 troops sent by governors as early as February. By May, Jefferson Davis was pushing for 100,000 men under arms for one year or the duration, and that was answered in kind by the U.S. Congress.

In the first year of the war, both sides had far more volunteers than they could effectively train and equip. After the initial enthusiasm faded, reliance on the cohort of young men who came of age every year and wanted to join was not enough. Both sides used a draft law—conscription—as a device to encourage or force volunteering; relatively few were actually drafted and served. The Confederacy passed a draft law in April 1862 for young men aged 18 to 35; overseers of slaves, government officials, and clergymen were exempt.  The U.S. Congress followed in July, authorizing a militia draft within a state when it could not meet its quota with volunteers. European immigrants joined the Union Army in large numbers, including 177,000 born in Germany and 144,000 born in Ireland.

When the Emancipation Proclamation went into effect in January 1863, ex-slaves were energetically recruited by the states, and used to meet the state quotas. States and local communities offered higher and higher cash bonuses for white volunteers. Congress tightened the law in March 1863. Men selected in the draft could provide substitutes or, until mid-1864, pay commutation money. Many eligibles pooled their money to cover the cost of anyone drafted. Families used the substitute provision to select which man should go into the army and which should stay home. There was much evasion and overt resistance to the draft, especially in Catholic areas. The great draft riot in New York City in July 1863 involved Irish immigrants who had been signed up as citizens to swell the vote of the city’s Democratic political machine, not realizing it made them liable for the draft.  Of the 168,649 men procured for the Union through the draft, 117,986 were substitutes, leaving only 50,663 who had their personal services conscripted.

In both the North and South, the draft laws were highly unpopular. In the North, some 120,000 men evaded conscription, many of them fleeing to Canada, and another 280,000 soldiers deserted during the war.  At least 100,000 Southerners deserted, or about 10 percent. In the South, many men deserted temporarily to take care of their distressed families, and then returned to their units.  In the North, "bounty jumpers" enlisted to get the generous bonus, deserted, and then went back to a second recruiting station under a different name to sign up again for a second bonus; 141 were caught and executed.

From a tiny frontier force in 1860, the Union and Confederate armies had grown into the "largest and most efficient armies in the world" within a few years. European observers at the time dismissed them as amateur and unprofessional, but British historian John Keegan's assessment is that each outmatched the French, Prussian and Russian armies of the time, and but for the Atlantic, would have threatened any of them with defeat.

Motivation

Perman and Taylor (2010) say that historians are of two minds on why millions of men seemed so eager to fight, suffer, and die over four years:

Some historians emphasize that Civil War soldiers were driven by political ideology, holding firm beliefs about the importance of liberty, Union, or state rights, or about the need to protect or to destroy slavery. Others point to less overtly political reasons to fight, such as the defense of one's home and family, or the honor and brotherhood to be preserved when fighting alongside other men. Most historians agree that no matter what a soldier thought about when he went into the war, the experience of combat affected him profoundly and sometimes altered his reasons for continuing the fight.

Prisoners

At the start of the civil war, a system of paroles operated. Captives agreed not to fight until they were officially exchanged. Meanwhile, they were held in camps run by their own army where they were paid but not allowed to perform any military duties.  The system of exchanges collapsed in 1863 when the Confederacy refused to exchange black prisoners. After that, about 56,000 of the 409,000 POWs died in prisons during the war, accounting for nearly 10 percent of the conflict's fatalities.

Naval war

The small U.S. Navy of 1861 was rapidly enlarged to 6,000 officers and 45,000 men in 1865, with 671 vessels, having a tonnage of 510,396.  Its mission was to blockade Confederate ports, take control of the river system, defend against Confederate raiders on the high seas, and be ready for a possible war with the British Royal Navy.  Meanwhile, the main riverine war was fought in the West, where a series of major rivers gave access to the Confederate heartland if the U.S. Navy could take control. In the East, the Navy supplied and moved army forces about and occasionally shelled Confederate installations.