Rise of the Abolition Movement

From the 1830s to the 1860s, a movement to abolish slavery in America gained strength in the northern United States, led by free blacks such as Frederick Douglass and white supporters such as William Lloyd Garrison, founder of the radical newspaper The Liberator, and Harriet Beecher Stowe, who published the bestselling antislavery novel "Uncle Tom's Cabin" (1852). While many abolitionists based their activism on the belief that slaveholding was a sin, others were more inclined to the non-religious "free-labor" argument, which held that slaveholding was regressive, inefficient and made little economic sense.

Free blacks and other antislavery northerners had begun helping fugitive slaves escape from southern plantations to the North via a loose network of safe houses as early as the 1780s. This practice, known as the Underground Railroad, gained real momentum in the 1830s and although estimates vary widely, it may have helped anywhere from 40,000 to 100,000 slaves reach freedom. The success of the Underground Railroad helped spread abolitionist feelings in the North; it also undoubtedly increased sectional tensions, convincing pro-slavery southerners of their northern countrymen's determination to defeat the institution that sustained them.

Western Expansion and Debate over Slavery in America

America's explosive growth–and its expansion westward in the first half of the 19th century–would provide a larger stage for the growing conflict over slavery in America and its future limitation or expansion. In 1820, a bitter debate over the federal government's right to restrict slavery over Missouri's application for statehood ended in a compromise: Missouri was admitted to the Union as a slave state, Maine as a free state and all western territories north of Missouri's southern border were to be free soil. Although the Missouri Compromise was designed to maintain an even balance between slave and free states, it was able to help quell the forces of sectionalism only temporarily.

In 1850, another tenuous compromise was negotiated to resolve the question of territory won during the Mexican War. Four years later, however, the Kansas-Nebraska Act opened all new territories to slavery by asserting the rule of popular sovereignty over congressional edict, leading pro- and anti-slavery forces to battle it out (with much bloodshed) in the new state of  Kansas. Outrage in the North over the Kansas-Nebraska Act spelled the downfall of the old Whig Party and the birth of a new, all-northern Republican Party. In 1857, the Supreme Court's ruling in the Dred Scott case (involving a slave who sued for his freedom on the grounds that his master had taken him into free territory) effectively repealed the Missouri Compromise by ruling that all territories were open to slavery. The abolitionist John Brown's raid at Harper's Ferry, Virginia, in 1859 aroused sectional tensions even further: Executed for his crimes, Brown was hailed as a martyred hero by northern abolitionists and a vile murderer in the South.

Civil War and Emancipation

The South would reach the breaking point the following year, when Republican candidate Abraham Lincoln was elected as president. Within three months, seven southern states had seceded to form the Confederate States of America; four more would follow after the Civil War (1861-65) began. Though Lincoln's antislavery views were well established, the central Union war aim at first was not to abolish slavery, but to preserve the United States as a nation. Abolition became a war aim only later, due to military necessity, growing anti-slavery sentiment in the North and the self-emancipation of many African Americans who fled enslavement as Union troops swept through the South. Five days after the bloody Union victory at Antietam in September 1862, Lincoln issued a preliminary emancipation proclamation, and on January 1, 1863, he made it official that "slaves within any State, or designated part of a State…in rebellion,…shall be then, thenceforward, and forever free."

By freeing some 3 million black slaves in the rebel states, the Emancipation Proclamation deprived the Confederacy of the bulk of its labor forces and put international public opinion strongly on the Union side. Some 186,000 black soldiers would join the Union Army by the time the war ended in 1865, and 38,000 lost their lives. The total number of dead at war's end was 620,000 (out of a population of some 35 million), making it the costliest conflict in American history.

The Legacy of Slavery

The 13th Amendment, adopted late in 1865, officially abolished slavery, but freed blacks' status in the post-war South remained precarious, and significant challenges awaited during the Reconstruction period (1865-77). Former slaves received the rights of citizenship and the "equal protection" of the Constitution in the 14th Amendment (1868) and the right to vote in the 15th (1870), but the provisions of Constitution were often ignored or violated, and it was difficult for former slaves to gain a foothold in the post-war economy thanks to restrictive black codes and regressive contractual arrangements such as sharecropping. 

Despite seeing an unprecedented degree of black participation in American political life, Reconstruction was ultimately frustrating for African Americans, and the rebirth of white supremacy–including the rise of racist organizations such as the Ku Klux Klan–had triumphed in the South by 1877. Almost a century later, resistance to the lingering racism and discrimination in America that began during the slavery era would lead to the civil rights movement of the 1960s, which would achieve the greatest political and social gains for blacks since Reconstruction.