Amerigo Vespucci was a banker, merchant, steward, ship business owner, and, most importantly, an explorer.
Amerigo was born in Italy in 1454 and died in Seville in 1512. He was probably in Spain when Christopher Columbus came back from his first journey to the New World and talked to the famous explorer.
When he heard about Christopher reaching what he thought was China, he decided to see it for himself, so he joined a journey to the new world as a navigator, and started out.
The fleet of four ships didn't get to North America, instead, it veered off course… a bit too much south, perhaps. Amerigo Vespucci had made it to South America, where he might have discovered the Amazon River.
At this point, Amerigo still thought that he had made it to China, so he outfitted another journey, but this time didn't get permission from the Spanish government to set sail.
He went to Portugal, where he was funded, and set sail again, claiming to have made it to Guanabara Bay (in Brazil) and even to Río de la Plata (between Argentina and Uruguay). During this voyage, Amerigo recognized that they were not in China, but that it was a “New World”.
In 1507, Martin Waldseemüller made a world map with “America” as the name for the New World because Amerigo was the first to recognize that these continents were not part of Asia.