The Americas were named for Explorer Amerigo Vespucci.
Credit: Jon Sullivan via Wikipedia
The naming of America goes to show that it pays to have a good publicist. When Christopher Columbus returned from his first voyage, he spoke (incorrectly) of wonderful discoveries off the coasts of Japan and India. The prospect of a new route to Asia excited his countrymen, but it did not grip Europe as would the discovery of a new continent.
In 1502 the Florentine merchant and explorer Amerigo Vespucci, on his second voyage across the Atlantic, began to suspect Columbus’ error. In letters to friends he spoke of a "Mundus Novis," or "New World." This grander description sparked celebration throughout Europe, and soon after a group of cartographers, poets and noblemen in France produced a popular pamphlet in which modern-day South America is named for the Italian explorer.
Of course, both Columbus and Amerigo fare well in history books considering that the Vikings beat them to the New World by 500 years.