Amerigo Vespucci, (1454-1512). Florentine navigator and explorer. Vespucci was originally a provision con-tractor at Seville, whose services were used by Christopher Columbus on one of his expeditions. He subsequently made several voyages to the New World (1497-1504) on Spanish and Portuguese expeditions. Al-though Vespucci claimed that he had reached the mainland of America in 1497, there is little other evidence to confirm this. His account of these explorations led to the naming of the new continent after his Christian name.