Americo-Liberians are a Liberian ethnicity of African American descent. The sister ethnic group of Americo Liberians are the Sierra Leone Creole people who are of African American, West Indian, and liberated African descent. Liberia: History, Geography, Government, and Culture, Infoplease.com Americo Liberians trace their ancestry to free-born and formerly enslaved African-Americans (who called themselves Americo Liberians) who immigrated in the 1800s to become founders of Liberia and other col… (More on Americo-liberian)