Vespucci was an important Italian, he was the first one to say that the "New World" was not part of Asia, but a different continent.
Vespucci was born in 1415, lived in Florence, Italy. Instead of going to a university, like his brothers, Vespucci learned the trade of a merchant, and enjoyed it. Then he was hired by Lorenzo Medici to be a clerk, in the commercial house of the Medici.
Due to his job, he went to Spain where he supplied some of Christopher Columbus's journeys to the New World. He also met with Columbus and was inspired to visit the New World himself.
In 1499, King Manuel I of Portugal asked Vespucci to travel with on several journeys to South America. He kept a record of these voyages and intended to published the book when he returned.
Vespucci became a very good navigator of Spain, he selected and trained other people and continued to gather information from the New World, until his death in 1512 from malaria.
In 1507, Martin Waldseemuller made a map from his books and named the new continent "America". This is how America got its name from America Vespucci.