Many Americans at the turn of the century believed that slavery was not sustainable and would either die of its own volition or be forced to end. However, many of these same people did not believe that former slaves could or should be absorbed into American society. Their solution was to find a way to repatriate former slaves to Africa. The American Colonization Society (ACS) was founded on December 16, 1816, at a meeting in Washington attended by Henry Clay, John Randolph, Richard Bland Lee, and Rev. Robert Finley. Its goal was to take free blacks back to Africa and to establish a colony for them to settle.

The first president of the society, Bushrod Washington, was a Supreme Court Justice. Many leading politicians from both the North and the South supported the society. One of the key supporters of the plan was President Monroe, who convinced Congress to appropriate $100,000 for the project.

In January 1820, the Elizabeth, the first ship, sailed from New York carrying three agents of the ACS and 88 emigrants. The ship arrived in Africa at Freetown, Sierra Leone. It then sailed south to what is now the northern coast of Liberia, where they attempted to establish a settlement. In the first three weeks, the three representatives of the ACS and 22 emigrants died of yellow fever. The remaining prospective settlers returned to Freetown to await the arrival of the next ship. An additional ship was sent, and with some military help, they were able to buy land on Mesurado Bay and establish a settlement. Over the next few years, the settlement grew despite opposition from local tribes. In its first decade of operation, the ACS brought 2,628 African Americans to the colony. The U.S. government also brought any slaves freed by intercepting slave ships to the colony. The ACS continued to support the colony, and in 1847, Liberia declared itself independent.

The role of the ACS in history remains controversial to this day. From the time it was established, many abolitionists opposed the organization, stating it was just a tool for maintaining slavery. Others argued it was inherently racist, as its goal was to remove blacks from the United States and return them to Africa. On the other hand, many black abolitionists supported the society and its successful transport of 13,000 African Americans to Africa, where they established a mostly successful colony-nation: Liberia.