William Walker (May 8, 1824 – September 12, 1860) was an American physician, lawyer, journalist and mercenary, who organized several private military expeditions into Latin America, with the intention of establishing English-speaking
colonies under his personal control, an enterprise then known as "
filibustering." Walker usurped the
presidency of the Republic of
Nicaragua in 1856 and ruled until 1857, when he was defeated by a coalition of Central American armies. He was executed by the government of
Honduras in 1860.