In his time William Walker was known as the Grey Eyed Man of Destiny, probably because the Grey Eyed Man of SUPER Racism wasn't as catchy. He was the most successful of the "filibusters" men who tried to conquer territory in other countries to add to the number of slave states in the United States. His first attempt was an invasion of Mexico which didn't go so well, but it made him popular enough to convince some Nicaraguans to invite him to come and try to invade THEIR country.