Columbus day exists only as a sop to Catholic voters. That’s it. He never set foot on any land that would become the US. In fact, he never set foot in North America. The country he represented and the religion he practiced were not part of the colonization of the land that became the United States. Was he some kind of evil villain? No. Is he any kind of material contributor to the country we have? No.
If Columbus had never sailed in 1492, the existence of the New World would not have remained unknown to Europeans much longer--in 1500 a Portuguese ship trying to get to India got off course and discovered Brazil.