Celebrating the Day of the Dead--No, No, Columbus Day

Today is a federal holiday in the United States dedicated to the memory of Christopher Columbus, an Italian sailing for a Spanish government which was one of the most religiously repressive regimes of all time. They killed or banished those who disagreed with them, and Columbus's arrival in the Americas wound up leading to the deaths of millions of the indigenous people in the New World, even if his intent was "only" to enslave them. Remind me again why we celebrate this?