- "Try Amerigo out. I bet after several years you'll name your shipping company after him."
- ―Cristina Vespucci to Lorenzo de' Medici.[src]
Amerigo was born in Florence, and initially worked as a clerk for the House of Medici, establishing relations with various merchants. He also took an interest in the voyage of Christopher Columbus. During a dinner party, Amerigo's cousin Cristina convinced the Florentine ruler Lorenzo de' Medici to hire him as a sailor and navigator.
On 14 May 1501, Amerigo's third voyage across the Atlantic Ocean began, eventually reaching Rio de Janeiro and Río de la Plata. He returned to Lisbon in 1504, having discovered what is known today as South America and pointing out that the newly discovered territories were not part of Asia.
In 1506, Amerigo interrogated and tortured Micheletto Corella in the Palazzo della Signoria in Florence, with Piero Soderini and the secret Assassin Niccolò Machiavelli. The following year, German cartographer and clergyman Martin Waldseemüller suggested that part of the Brazilian territory discovered by Amerigo be named in his honor.