America was "discovered" in different senses at different times:

• Indigenous peoples first arrived in the Americas tens of thousands of years ago, with archaeological evidence pushing human presence back to possibly 21,000 to 30,000 years ago or more. They likely migrated from Asia via a land bridge called Beringia or by sea.

• The Norse, led by Leif Erikson, were the first known Europeans to reach North America around 1000 AD, establishing a short-lived settlement at L'Anse aux Meadows in Newfoundland.

• Christopher Columbus is credited with the European "discovery" of America in 1492 when he landed in the Caribbean islands on October 12, opening the way for European exploration and colonization. However, he did not realize he had found a previously unknown continent, thinking he reached Asia.

• Giovanni Caboto (John Cabot) is credited with discovering the continental coast of North America for England in 1497, landing on Newfoundland.

The name "America" was given in 1507 based on the recognition by Amerigo Vespucci that the lands found were a New World, not Asia.

In summary, while Columbus's landing in 1492 is often cited as the discovery of America in Western history, humans had been living in the Americas for tens of thousands of years, and there had been prior European contact by the Norse around 1000 AD.

The most commonly cited date for the "discovery" of America by Europeans is October 12, 1492, when Columbus reached the Caribbean.