No disrespect toward Columbus. The man was a visionary and risk-taker. But it was Amerigo Vespucci who discovered the Northern part of the continent which is now the USA.
After all, our country is named after him, AMERIGO=AMERICA.
Amerigo Vespucci's New World travels are basically limited to coastal South America and some of the West Indies. According to all available records, he never went north of Hispaniola.
The reason Amerigo Vespucci is remembered at all lies in the fact that he demonstrated that the New World was indeed an entirely separate landmass, hitherto unknown to Afro-Eurasians. This confirmed many people's suspicions about Columbus' erroneous claim that they had found Asia's eastern outskirts - the Earth's circumference, as well as the rough distance from Europe to eastern Asia was already more or less established by that time, so anyone who did the math knew that the new lands were much too close to even be associated with Asia.
For this reason, the entire supercontinent known as the 'New World' was to be named in honor of Mr Vespucci (as well as the fact that Columbus, due to his behavior and unpleasant personality, was known for easily making enemies of politically influential people and had fallen largely out of disfavor in many European courts).
Also, I should emphasize that the word 'AMERICA' refers to the whole of the 'New World', not just one country or continent. North America, the West Indies, Central America, and South America are the whole of AMERICA. The USA is the United States of America - ie a union of federated states that lie within America - and is no more or less American than Brazil, Cuba, Mexico, or Canada. Although it became commonplace to [incorrectly] refer to people from the USA as 'Americans' so as to differentiate them from other nationalities, the title still remains applicable to anyone from the Americas.
The Organization of American States (OAS) would back me up on this one too.
In short due to the fact that in his disgrace his contributions to the discovery of America were not recognised by Spain who instead chose to promote Vespucci's discoveries. America was named by a German cartographer called Martin Waldseemüller. He was the first person to publish a wide spread world map featuring the New World. He used Vespucci's publications (which to be fair were very substantial) as his primary source, he had never even heard of Columbus. Therefore when he published the map he identified the new continent (which at the time only included the Northern part of South America) as America. When North America was discovered geographers chose to continue the trend of calling the new world the Americas.
I've had a lot of sobering thoughts in my time Del Boy, it's them that started me drinking!
Columbus was under the impression that he had found a new route to east India (hence naming the native Americans 'Indians'). A belief that persisted until he died.
Amerigo Vespucci was the first explorer, after Columbus, to note that the land Columbus had found was not east India, but a entirely new continent.
In 1507, Martin Waldseemüller produced a world globe and a large world map (Universalis Cosmographia) bearing the first use of the name "America".
In 1513, Waldseemüller appears to have had second thoughts about the name, probably due to contemporary protests about Vespucci’s role in the discovery and naming of America. In his reworking of the Ptolemy atlas (written with Ringmann), the continent is labelled simply Terra Incognita (unknown land). Despite the revision, 1,000 copies of the world map had since been distributed, and the original suggestion took hold. While North America was still called Indies in documents for some time, it was eventually called 'America' , as well.
To put the name "America" in the maps was a mistake of a german cartographer somewhen in the early XVI century but the name America remained since then in the history.
Why not John Cabot (Giovanni Caboto as named in his native Italy) Day? Columbus never set foot in any territory that became part of the 50 states of the USA.
And why do we celebrate the Pilgrims landing at Plymouth Rock in 1620, or the Jamestown colony from 1607? The Spanish were living in Florida much earlier, starting the city of St. Augustine in 1565. They even had forts as far north as South Carolina.