January 31, 1865: The Thirteenth Amendment is ratified.

The Thirteenth Amendment to the U.S. Constitution was the first to be passed in sixty years, the first since the passage of Twelfth Amendment in 1804. The Amendment had two simple and short sections:

Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.

Congress shall have power to enforce this article by appropriate legislation.

Its passage, however, was anything but. In 1863, Abraham Lincoln issued the Emancipation Proclamation, which declared that any enslaved person in any state in rebellion against the United States “shall be then, thenceforward, and forever free” - a more symbolic than practical gesture. Without a constitutional amendment, however, the Emancipation Proclamation could easily be swept aside as a wartime measure and a gross overreach of presidential powers, unnecessary in a postwar, reunited United States, and four million slaves would remain in bondage.

In January of 1864, Senator John B. Henderson, a Democrat representing the slave/border state of Missouri, proposed a ban on slavery via constitutional amendment. Less than a month later, Charles Sumner, a Radical Republican, proposed an amendment as well, though his version not only banned slavery but contained a guarantee of equality, a clause that never made it into the final amendment. The Senate passed the amendment in April of 1864 38 to 6, but the House of Representatives took another long grueling eight months to debate and discuss it; meanwhile, the Republican party adopted, as part of its official platform, support for an antislavery amendment. Finally, on January 31, the House of Representatives passed the amendment by a narrow margin - 119 to 56. 

The Thirteenth Amendment was not officially adopted until December of 1865, months after Lincoln’s assassination. The first state to ratify was Illinois, and the twenty-seventh state (out of thirty-six - a 3/4ths majority) was Georgia, while Kentucky and Mississippi rejected the initial proposals and failed to ratify the amendment until 1976 and 1995, respectively.