Before the outbreak of war in April 1861, the American republic had survived diplomatic and military crises and internal stresses. It weathered tensions with France in the late 1790s, a second war with Britain in 1812–1815, and disputes regarding international boundaries. Political wrangling over economic issues such as the tariff, a national bank, and government-supported public works (called internal improvements in the nineteenth century) proved divisive but posed no serious threat to the integrity of the Union. Despite fissures along ethnic and class lines, the majority of Americans had much in common. They were white, Christian, spoke English, and shared a heritage forged in the crucible of the Revolutionary War.

Questions relating to the institution of slavery set the stage for secession and war. Most men and women at the time would have agreed with Abraham Lincoln’s assertion in his Second Inaugural Address that slavery “was, somehow, the cause of the war.” Alexander H. Stephens, the Confederacy’s vice president, minced no words when he proclaimed in March 1861 that slavery “was the immediate cause of the late rupture and the present revolution” to establish southern independence.[1] The framers of the United States Constitution had compromised regarding slavery, creating a democratic republic that sought to ensure its citizenry’s freedoms while also reassuring the South that individual states would have the power to maintain and regulate slavery within their boundaries. The paradox of white liberty that rested in part on a foundation of black slavery was thus imbedded in the origins of the United States.

Debates over the expansion of slavery into federal territories, which were tied to the South’s effort to maintain an equal number of free and slave states, created turmoil in national politics. The Missouri Compromise of 1820, the Wilmot Proviso of 1846