William Walker was an American adventurer who was born in 1824 in Nashville, Tennessee and was educated at the University of Nashville. He earned a medical degree while still in his teens and then began to study law. After completing those studies, he took the exam and was admitted to the bar in New Orleans, Louisiana. He worked as a lawyer for a while and then moved on to journalism and finally settled down to the life of a soldier of fortune, all while still in his twenties. Walker moved to California in 1850 and led an armed invasion of Baja Califonia, Mexico three years later. He proclaimed himself the president of the new independent republic of Sonora and Baja California after his successful invasion. However, he soon ran out of supplies and surrendered to the US authorities. He was taken to court on charges of violating neutrality laws, but was acquitted in 1854.
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In 1854, the Liberal party in Nicaragua was fighting the Conservative party for power and losing. In desperation, they sought out Walker's military assistance to help them topple the Conservatives. So, in 1855, Walker responded and led them in the capture of the city of Granada. He double-crossed the Liberals, however, and made himself president of Nicaragua in 1856 and was quickly recognized by the United States government as such. He proceeded to declare English as the official language and attempted to become a United States slave- state. Walker's ambitious plan was to unite all of Central America into one country under his rule. However, Walker's supporters appropriated a transit company owned by the American industrialist Cornelius Vanderbilt and Vanderbilt retaliated by financing the Conservative forces against Walker. Walker was overthrown in a battle in 1857, and despite his attempts to recapture Nicaragua he never again regained control. The British captured Walker in Honduras in 1860 during another takeover attempt and he was promptly executed by the Honduran authorities.