1865 Thirteenth Amendment abolishes slavery
Amendment XIII (the Thirteenth Amendment) of the United States Constitution officially abolished slavery and, with the exception of allowing punishments for crimes, prohibits involuntary servitude. In actuality the Amendment affected only Delaware and Kentucky. Everywhere else slavery had been abolished by state action or the Emancipation Proclamation. Abraham Lincoln was the main author of the Amendment, insisting it was needed to guarantee the permanent abolition of slavery.
The article states:
Section 1. 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.
Section 2. Congress shall have power to enforce this article by appropriate legislation.
The thirteenth amendment to the Constitution of the United States was proposed to the legislatures of the several states by the Thirty-eighth Congress, on January 31, 1865. Although it was ratified by the necessary three-quarters of the states within a year of its proposal, its most recent ratification occurred as recently as 1995, in Mississippi, which was the last of the thirty-six states in existence in 1865 to ratify it.