Vespucci was born in 1454 to a prominent family in Florence, Italy. As a young man he read widely and collected books and maps. He began working for local bankers and was sent to Spain in 1492 to look after his employer's business interests.
While in Spain, Amerigo Vespucci began working on ships and ultimately went on his first expedition as a navigator in 1499. This expedition reached the mouth of the Amazon River and explored the coast of South America. Vespucci was able to calculate how far west he had traveled by observing the conjunction of Mars and the Moon.
On his second voyage in 1501, Amerigo Vespucci sailed under the Portuguese flag. After leaving Lisbon, it took Vespucci 64 days to cross the Atlantic Ocean due to light winds. His ships followed the South American coast to within 400 miles of the southern tip, Tierra del Fuego.
While on this voyage, Vespucci wrote two letters to a friend in Europe. He described his travels and was the first to identify the New World of North and South America as separate from Asia. (Until he died, Columbus thought he had reached Asia.)
Amerigo Vespucci also described the culture of the indigenous people, and focused on their diet, religion, and what made these letters very popular - their sexual, marriage, and childbirth practices. The letters were published in many languages and were distributed across Europe (they were a much better seller than Columbus' own diaries).
Amerigo Vespucci was named Pilot Major of Spain in 1508. Vespucci was proud of this accomplishments, "I was more skillful than all the shipmates of the whole world." Vespucci's third voyage to the New World was his last for he contracted malaria and died in Spain in 1512 at the age of 58.
The German clergyman-scholar Martin Waldseemuller liked to make up names. He even created his own last name by combining words for "wood," "lake," and "mill." Waldseemuller was working on a contemporary world map, based on the Greek geography of Ptolemy, and he had read of Vespucci's travels and knew that the New World was indeed two continents.
In honor of Vespucci's discovery of the new forth portion of the world, Waldseemuller printed a wood block map (called "Carta Mariana") with the name "America" spread across the southern continent of the New World. Waldseemuller printed and sold a thousand copies of the map across Europe.
Within a few years, Waldseemuller changed his mind about the name for the New World but it was too late. The name America had stuck. The power of the printed word was too powerful to take back. Gerardus Mercator's world map of 1538 was the first to include North America and South America. Thus, continents named for a Italian navigator would live on forever.