Columbus Day, annually set on the second Monday of October, remembers Christopher Columbus' arrival to the Americas on October 12, 1492. The day was honored for hundreds of years, but did not become a federal holiday until 1937 when President Franklin D. Roosevelt declared it so after a campaign by the Knights of Columbus.
It was always celebrated on October 12 until 1971, when it was moved to the second Monday of the month.
The Italian-born explorer had set sail two months earlier: he intended to chart a western sea route to China, India and the fabled gold and spice islands of Asia; instead, he landed in the Bahamas, becoming the first European to explore the Americas since the Vikings set up colonies in Greenland and Newfoundland during the 10th century. Later that month, Columbus arrived at Cuba and believed it was China; in December the expedition found Hispaniola, which he though might be Japan.
By his third journey across the Atlantic, he realized that he hadn’t reached Asia but instead had stumbled upon a continent.