History is history and Christopher Columbus ushered in the European “Age of Discovery” in 1492.
Although there may have been many forays by previous explorers, Asians, Vikings, etc., into what is now known as the Americas; it was following Christopher Columbus’ exploration into the “New World” which, yes, was inhabited by what we call indigenous people, that expanded worldwide European civilization.
Discovering the discovered is still discovery.
There has been a movement afoot for some time (since 1954) to eliminate Columbus Day (first celebrated in 1938) as a national holiday. It has become fashionable for some people, through ignorance of history and the influence of revisionists’ historic propaganda to bash Christopher Columbus and his accomplishments.