TIL there is a theory that Columbus' Navigator, William Harris AKA Guillermo Herries, an Irishman from Galway, had actually sailed to the Americas before 1492.
Yes. People already existed here, the Vikings visited first (and most say the Irish too), Columbus didn't "discover" shit. Only thing he did was rape, pillage, and enslave. And we have a holiday dedicated to him...
TL;DW - There are carvings, stories, genetic evidence, linguistic evidence, and historical accounts that collectively support the idea that contact by the Irish (and maybe other Europeans) occurred 1000 years before Columbus and this dude in Galway knew about it from trying and then might have been in cahoots with Columbus to go there, but Columbus took all the credit as an "accidental" discovery.