Liberia was formed as an independent African state in 1847. The governing class in Liberia was formed by freed African slaves from the United States. Between 1820-1990 nearly 17,000 ex-slaves re-settled in Liberia. The descendents of these immigrants controlled Liberia for almost 150 years. The United States recognized the independence of Liberia. This recognition protected Liberia from being colonized by European powers.