Although many white Americans supported the ACS, free blacks were nearly unanimous in their condemnation of colonization, viewing it as little more than a wholesale deportation scheme. As a consequence, only about 4,000 free African Americans and 7,000 former slaves (freed on the condition that they immigrate) settled in Liberia between 1820 and 1864. Those who did go faced many challenges. The mortality rate from disease was extremely high, and relations between the colonists and Liberia's indigenous peoples were often strained.
Under the aegis of the ACS, a white "agent" governed the colony, but in 1839 the first steps toward self-rule were taken, and the colony became a Commonwealth. Under a new constitution, legislative powers were shared by the ACS-appointed governor and a popularly elected council. Although the first governor of the commonwealth was white, his successor was Joseph Jenkins Roberts, a freeborn native of Virginia who became Liberia's first black chief executive in 1841.
In 1847, with the blessing of the ACS, Liberia declared its independence and adopted a constitution modeled on that of the United States. Although Liberia was the first republic established on the African continent, it was denied diplomatic recognition by the United States until 1862, because of southern opposition to accrediting a black diplomat in Washington.