Columbus Day is a holiday in the United States commemorating the anniversary of Christopher Columbus's arrival in the Americas, which happened on October 12, 1492 in the Julian calendar, or October 21, 1492 in the modern Gregorian calendar. Full reference found HERE.

Image: "Columbus" by Sebastiano del Piombo, 1519

Indigenous People's Day is a holiday in the United States that celebrates and honors Native American peoples and commemorates their histories and cultures.