Timeline of events leading to the American Civil War

The events which led to the origins of the American Civil War and to the Civil War itself may be considered in two periods, the long term build up over many decades and the five-month build up to war in the period immediately after the election of Abraham Lincoln as President (in November 1860) and the fall of Fort Sumter (in April 1861). Over many years from almost the beginning of the colonial period in Virginia, events, occurrences, actions and statements by politicians and others in the United States brought about issues, differences, tensions and divisions between the leaders and people of the slave states of the Southern United States and the leaders and people of the free states of the Northern United States (including Western states). The big underlying issue from which other issues developed was whether slavery should be retained and even expanded to other areas or whether it should be contained and eventually abolished. Over many decades, these issues and divisions became increasingly irreconcilable and contentious. Events in the 1850s culminated with the election of the anti-slavery, but not yet abolitionist, Abraham Lincoln as President of the United States. This provoked the first round of State secessions as leaders of the Deep South States were unwilling to trust Lincoln not to move against slavery. This timeline briefly describes and links to narrative articles and references about many of the events and issues which historians recognize as causes of the Civil War. The series of events for the period from Lincoln's election on November 6, 1860 through the fall of Fort Sumter and Lincoln's call for volunteers to suppress the rebellion on the next day, April 15, 1861, led to the breaking point and civil war. The timeline shows many key events and statements in this crucial period immediately before hostilities began. The entries that finish this timeline include a few more events in the following months in 1861 that relate to the secession of four additional states and further initial actions and occurrences as both groups of states prepared for war. Four additional states, the Upper South States of (Virginia, North Carolina, Tennessee and Arkansas) completed the formation of the Confederate States of America during this period. Their addition to the Confederacy insured a war would be prolonged and bloody because they contributed many men and resources to the Confederacy. Initially, only the seven Deep South States, with economies based on cotton (then in heavy European demand with rising prices) of Alabama, Florida, Georgia, Louisiana, Mississippi, South Carolina and Texas seceded. President Lincoln's call for volunteers to suppress the rebellion pushed the four other Upper South States also to secede.

Robert Francis Engs described the issues which caused the Civil War in Slavery during the Civil War in The Confederacy edited by Richard N. Current at page 983:
 * Although slavery was at the heart of the sectional impasse between the North and South in 1860, it was not the singular cause of the Civil War. Rather, it was the multitude of differences arising from the slavery issue that impelled the Southern States to secede....The new republic claimed its justification to be the protection of state rights. In truth, close reading of the states' secession proclamations and of the new Confederate Constitution reveal that it was primarily one state right that impelled their separation: the right to preserve African American slavery within their borders....Thus, the North went to war to preserve the Union, and the white South went to war for independence so that it might protect slavery.

Historian, James M. McPherson, similarly stated on the first page of his 1982 one-volume history of the Civil War and Reconstruction, Ordeal By Fire: The Civil War and Reconstruction:
 * The social and political strains produced by rapid growth provoked repeated crises that threatened to destroy the republic. From the beginning, these strains were associated mainly with slavery. The geographical division of the country into free and slave states ensured that the crises would take the form of sectional conflict. Each section evolved institutions and values based on its labor system. These values in turn generated ideologies that justified each section's institutions and condemned those of the other.

McPherson notes at page 2 that "as early as 1787, conflict over slavery at the constitutional convention almost broke up the Union before it was fairly launched." He further stated at page 51 of Ordeal by Fire that:
 * Slavery was the main issue in national politics from 1844 to the outbreak of the Civil War. And many times before 1844 this vexed question burst through the crust of other issues to set section against section, as in the Missouri debates of 1819–1820. Even the nullification crisis of 1832, ostensibly over the tariff, had slavery as its underlying cause. The South Carolina nullifiers feared that the centralization of government power, as manifested by the tariff, might eventually threaten slavery itself. Nullification was the most extreme assertion of states' rights – a constitutional theory whose fundamental purpose was to protect slavery against potential federal interference.

At first, all the American colonies allowed slavery but over the period from 1777 to 1804, Northern states abolished it or provided for its gradual abolition within their borders. Thereafter, the Northern and Southern states gradually grew apart over slavery and a number of issues related directly or indirectly to slavery, as the historians who have studied and written about the war in depth have pointed out. Other issues that developed in association with the complex issue concerning the institution and retention of slavery in the United States included competing understandings between the Northern and Southern sections of the country relating to federalism and the powers of the federal and state governments, differences in party politics, preference or opposition to national expansion and to where it would or could occur, differing theories of economics and labor, preferences for and against tariffs and federally-financed internal improvements, industrialization versus agrarianism, sectionalism, and differences in social structures and general values.

The leaders and citizens of the various sections developed increasingly strident and irreconcilable positions about the existence and expansion of slavery and other issues during the 1850s. The slave states began to believe they were losing ground in these arguments and that the institution of slavery was increasingly threatened. The leaders of the Deep South States in particular reacted to the election of Abraham Lincoln as President of the United States on November 6, 1860 on a platform that called for the end of the expansion of slavery with professed fears that the Northern States and their leaders would soon try to abolish slavery altogether. No longer able, or perhaps no longer willing, to compromise or attempt to compromise on the issues which divided the sections of the country, the seven Deep South States gave up on the political process and seceded from the Union of the United States even before the inauguration of Lincoln as President. The onset of the Civil War in April 1861 occurred with only these seven Deep South States having passed ordinances of secession and joined the Confederacy. Soon after Lincoln's call for volunteers to suppress the rebellion on April 15, 1861, the four Upper South States joined the Confederacy. Some people from the Upper South states in particular adhered to the Union but significant minorities in the border slave states of Kentucky, Maryland and Missouri, which remained in the Union, also supported the Southern cause.

This timeline is a chronological list of events, statements, writings and influences that historians such as James McPherson, David J. Eicher, Harry Hansen, John Bowman, E. B. Long, Margaret Wagner and others have cited and associated with the issues of slavery and other issues that led to the build up to and outbreak of the American Civil War.