Columbus Day first became
a holiday in 1906 in Colorado,
and it officially became a federal holiday in 1937. In 1937, President Franklin D. Roosevelt
proclaimed Columbus Day a national holiday, as a result of
intense lobbying by the Knights of Columbus. Originally observed every October 12,
it was fixed to the second Monday in October in 1971.
Source: http://www.history.com/topics/columbus-day
