A republic occupying the western third of the island of Hispaniola in the West Indies. The Spanish occupied the island after its discovery by Columbus in 1492, enslaving the Indian population, which was soon exterminated. In time, the Spanish partially abandoned the island, and the western portion became a base for pirates. This area gradually came under French control, which was recognized by Spain in 1697. Under the French, African slaves were imported to work the sugar plantations, which were the mainstay of the colony's economy. In 1804, the descendants of these slaves expelled their French masters. The Republic of Haiti split into two parts in 1811, but in 1820, it was reunited and enlarged by the conquest of the eastern portion of the island (lost in 1844). During the 19th century, anarchy and foreign indebtedness increased, finally bringing U.S. occupation in 1915. U.S. troops withdrew in 1934, and the last U.S. controls ended in 1941. From 1957 to 1986, Haiti was ruled by the Duvaliers, first by Dr. Francois Duvalier ("Papa Doc") and, after his death in 1971, by his son, Jean-Claude ("Baby Doc"). After a period of popular unrest, Jean-Claude Duvalier fled Haiti in 1986, and the country's politics since have been chaotic. U.S. troops interceded in 1994-96 to restore the popularly elected president, who had been overthrown by the Haitian military. A small contingent of U.N. peacekeeping troops remain in Haiti.