Reason for exploring
Amerigo first sailed with Christopher Columbus. He was there when they discovered land. Amerigo didn't think that they found Asia. He went back to prove that America was a different continent. And he did just what he wanted to.
Explored for who?
Amerigo Vespucci explored for Spain. After Christopher Columbus's voyage, he thought that if Spain let Christopher get supplies from, they would let Amerigo. And so they did. The king and queen then was Ferdinand and Isabella. They also ruled when Christopher got his loan.
Map of Spain. (Above) Flag of Spain. (Below)