The biggest question facing the leaders of the United States in the early 19th century was what to do about slavery. Should it continue or should the U.S. abolish it? Could the country really be home to free Black people and enslaved black people at the same time? And if the U.S. ended slavery, would freed men and women remain in the country or go somewhere else?

Many white people at this time thought the answer to that last question was to send free Black Americans to Africa through “colonization.” Starting in 1816, the American Colonization Society—which counted future presidents James Monroe and Andrew Jackson among its members—sought to create a colony in Africa for this purpose.

This was 50 years before the U.S. would abolish slavery. Over the next three decades, the society secured land in West Africa and shipped people to the colony, which became the nation of Liberia in 1847.

The society spent its first few years trying to secure land in West Africa. In 1821, it made a deal with local West African leaders to establish a colony at Cape Mesurado. The strip of land was only 36 miles long and three miles wide (today, Liberia stretches over 38,250 square miles) The next year, the society began sending free people—often groups of families—to the colony. Over the next 40 years, upwards of 12,000 freeborn and formerly enslaved Black Americans immigrated to Liberia.

The American Colonization Society was distinct from Black-led “back to Africa” movements that argued Black Americans could only escape slavery and discrimination by establishing their own homeland, says Ousmane Power-Greene, a history professor at Clark University and author of Against Wind and Tide: The African American Struggle against the Colonization Movement. Though some free Black Americans may have supported the society’s mission, there were also plenty who criticized it.

“They argue that their sweat and blood, their family who were once enslaved, built this country; so therefore they had just as much right to be here and be citizens,” he says. In addition, many argued “this is a slaveholders’ scheme to rid the nation of free Blacks in an effort to make slavery more secure.”

In the beginning, the American Colonization Society didn’t uniformly believe that slavery should end. The society was made up of white men from the north and south, including slave owners who felt that free Black people undermined the institution of slavery, and should be sent away. Others in the society felt that slavery should be gradually dismantled, but that Black people could never live freely with white people.

As the abolitionist movement grew in the early 1830s, abolitionists’ criticism of the society began to erode its support. Unlike the white people in the American Colonization Society who believed that slavery should gradually end, abolitionists called for an immediate end to slavery. In addition, many abolitionists considered it cruel to deport Black Americans to Liberia, where they struggled to survive in a new environment with new diseases.

In 1854, future president Abraham Lincoln agreed with this sentiment when he gave a speech that mentioned colonization as an appealing solution to the moral evils of slavery—but noted its logistical and ethical challenges:

“If all earthly power were given me, I should not know what to do, as to the existing insti­tution. My first impulse would be to free all the slaves, and send them to Liberia,–to their own native land. But a moment’s reflection would convince me, that whatever of high hope, (as I think there is) there may be in this, in the long run, its sudden execution is impossible. If they were all landed there in a day, they would all perish in the next ten days; and there are not surplus shipping and surplus money enough in the world to carry them there in many times ten days."

In particular, the Black abolitionist Nathaniel Paul and the white abolitionist William Lloyd Garrison helped discredit colonization by debating its proponents in public. In the early 1830s, Garrison published a book called Thoughts on Colonization containing “big passages of Black Americans saying why it’s bad,” Power-Greene says. Among people who already believed slavery should end at some point, “abolitionists convince most people, particularly in the northeast, that the colonization movement is anti-Black.”

The American Colonization Society evolved throughout the 1830s so that by the end of the decade, it began to support immediate abolition while still promoting its colony in Africa as a place for free Black Americans to relocate. This caused the society to lose support among southern slave owners who were committed to preserving slavery.

Joseph Jenkins Roberts, a man born free in Virginia, became the colony’s first Black governor in 1841, and declared Liberia’s independence in 1847; it became the first African colony to gain independence. By then, the American Colonization Society had lost a lot of money and was falling apart. In its Declaration of Independence, Liberia accused the U.S. of injustices that made separation necessary, and urged other countries to recognize its statehood.

Still, the United States did not recognize Liberia as an independent nation until 1862, during the American Civil War. That year, enslaved people in Washington, D.C. won their freedom, and Congress approved funds to relocate those who wanted to move to Liberia or Central America. President Abraham Lincoln still believed at this late date that voluntary colonization should go hand-in-hand with emancipation because he thought Black and white people couldn’t live equally in the same country. Later in the war, however, Lincoln abandoned the idea of colonization and publicly supported Black men gaining the right to vote.