Simplify the following text for a Grade 12 native English-speaking person.
Original: Amerigo Vespucci ( March 9 , 1454-February 22 , 1512 ) was an Italian explorer , navigator and cartographer .
Simplified: Amerigo Vespucci ( March 9 , 1454 - February 22 , 1512 ) was an Italian merchant , explorer and cartographer .