Slavery helped bring about the deadliest military conflict in the history of the United States – the American Civil War. 

The Trans-Atlantic trading routes brought in more than 12 million enslaved Africans to the Western Hemisphere between 1525 and 1866. However, approximately 388,000 slaves were brought into North America with only 10.7 million surviving the voyage to the New World. The Abolition Movement was a key part of the fight to abolish slavery in the United States. 

Slavery in the United States was officially abolished on December 6, 1865, with the ratification of the 13th Amendment after it was passed by Congress on January 31, 1865. The amendment declares that "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."

Previously, the most significant effort to end slavery was made by President Abraham Lincoln in 1863 when he issued the Emancipation Proclamation which stated, "all persons held as slaves within any State, or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free." This, however, did not end Slavery because it only freed slaves in areas actively rebelling against the Union and not in the border states such as Kentucky or West Virginia. Therefore, Lincoln sought to make the 13th Amendment to abolish slavery the top priority of the Republican Party platform in the 1864 Presidential election. 

HOW LINCOLN, DOUGLASS EMERGED TO REUNIFY AMERICA IN 'THE PRESIDENT AND THE FREEDOM FIGHTER' 

Initially, the 14th Amendment passed the Senate but failed to pass in the House of Representatives in April 1864. However, after the 1864 election, the House voted in favor of the amendment with a vote of 119-56. In February 1865, Lincoln approved the resolution and submitted it for ratification in the state legislatures. Thereafter, the 14th and 15th Amendments soon joined the 13th in order to protect the civil rights of Americans in the aftermath of the Civil War.

JUNETEENTH: WHAT IS IT AND WHY DO WE CELEBRATE IT? 

The 13th amendment was ratified by the necessary three-fourths of states in December 1865. Mississippi became the last state of the four that voted not to ratify it. In 2013, Mississippi officially ratified the amendment after failing to make it official by notifying the US Archivist when the state legislature originally ratified it in 1995.