when was slavery abolished in usa

Slavery in the United States was officially abolished with the ratification of the 13th Amendment to the Constitution. The U.S. Congress passed the amendment on January 31, 1865, and it was ratified by the required states on December 6, 1865. The amendment abolished slavery and involuntary servitude throughout the United States and its territories, making chattel slavery illegal nationwide. Although the Emancipation Proclamation issued by President Abraham Lincoln in 1863 declared slaves in rebelling states to be free, it did not end slavery across the entire country because it only applied to Confederate states still in rebellion and not loyal border states. The 13th Amendment was necessary to guarantee the permanent abolition of slavery. Additionally, slavery in Native American territories, particularly among the "Five Civilized Tribes," was officially ended later in 1866 through treaties with the U.S. government. Thus, the legal end of slavery in the continental United States occurred with the ratification of the 13th Amendment on December 6, 1865, and the final abolition in Native American territories followed on June 14, 1866.