<P> It was soon understood that Columbus had not reached Asia, but rather found what was to Europeans a New World, which in 1507 was named "America", probably after Amerigo Vespucci, on the Waldseemüller map . </P> <P> In 1500, Pedro Álvares Cabral was sent by Portugal to explore South America . He is considered to be the discoverer of Brazil . </P> <P> Aragon King Ferdinand II sent Juan Ponce de León from the fledgling colony on Hispaniola to verify rumors of undiscovered land to the northwest . On April 2, 1513, Ponce de León disembarked on the northeast coast of what he named Florida for the crown . The exact location is disputed, but historians have offered the possibilities of St. Augustine, Ponce de León Inlet, and Melbourne Beach . He encountered the powerful Gulf Stream and found a passage through the Florida Keys to land on the southwestern Gulf Coast of Florida on the Gulf of Mexico . Again, the exact location is disputed . While it is true that Columbus visited Puerto Rico and the Virgin Islands in 1493, Ponce de Leon was the first known European to reach the present - day United States mainland . </P> <P> On September 25, 1513, Spanish conquistador Vasco Núñez de Balboa was the first European to see the Pacific Ocean once he crossed the Isthmus of Panama . He claimed all the territory touching it for the Crown, later to affect colonization of Las Californias . </P>

Who was the first european explorer to explore land that became part of the united states