Amerigo Vespucci was an Italian explorer, financier, navigator and cartographer who first demonstrated that Brazil and the West Indies did not represent Asia's eastern outskirts as initially conjectured from Columbus' voyages, but instead constituted an entirely separate landmass hitherto unknown to Old Worlders. Colloquially referred to as the New World, this second super continent came to be termed "Americas", deriving its name from Americus, the Latin version of Vespucci's first name.

https://en.wikipedia.org/wiki/Amerigo_Vespucci