Mississippi-in-Africa was a colony on the Pepper Coast (West Africa) founded in the 1830s by the Mississippi Colonization Society of the United States and settled by American free people of color, many of them former slaves. In the late 1840s, some 300 former slaves from Prospect Hill Plantation and other Isaac Ross properties in Jefferson County, Mississippi, were the largest single group of emigrants to the new colony. Ross had freed the slaves in his will and provided for his plantation to be sold to pay for their transportation and initial costs.
These freedmen and other American immigrants to the colony and its neighbors, Liberia (which annexed Mississippi-in-Africa in 1842) and Republic of Maryland (which merged with Liberia in 1857) developed as the Americo-Liberians, an ethnic group who formed a political and economic elite. They dominated what became the independent country of Liberia into the late 20th century, having taken power over the indigenous natives. The Mississippi colony was located in what is present-day Sinoe County, Liberia.