The Liberian colony was established in 1822 when freed slaves from the Americas returned to their homeland. A colony then developed into a federation, then a commonwealth, and it achieved independence in 1847 with a helping hand from the American Colonization Society (an organization based in the United States). Up until 1980, Americo-Liberians, generally known as descendants of the freed slaves, controlled the social and political structure in the country. Conflicts in Liberia have largely been caused by an unequal distribution of wealth and power resulting from the country's social structure.