“I wasn’t referring to the Indians. Although it does appear they came from somewhere else. I was referring to Lief Ericson. Also there’s evidence in South America of African settlers before then. And of course there’s the fact that Columbus landed in the Bahamas. He quite simply did NOT discover America.”
There is more to discovery than just arriving first. The important part is communicating that discovery to the world. Who cares if Joe Blow walked around on Cape Cod in 1105 but NEVER TOLD ANYONE ABOUT IT.
Lief Ericson established communication and trade. Really all Columbus did was point out the Americas to Southern Europe at a time when they were extremely interested in colonization. Somebody was going to do it eventually, could have been somebody else 10 years earlier or later, Europe was on that path.