On another note, the Welsh might have discovered America before Columbus. Perhaps even the Jews came over prior to the fall of the Roman Empire to escape persecution. One tribe (don't recall which one) has many similar beliefs to the Jews which is rather abnormal when you look at other tribes. Part of the reason why Jefferson sent Lewis and Clark west was to look for evidence of the Welsh and Jews besides mapping out the land a bit and looking for British and Spanish encampments. Given that there is a tribe in the Mississippi River area that has boats that are oddly VERY similar to the Welsh, it's too coincidental if they didn't come here prior to Columbus. DNA tests so far have disproved one tribe's ancestry being Jewish, but as far as I'm aware, the Welsh connection hasn't been disproven. That's not to say either the Jews or Welsh didn't come to America long ago. Maybe the local tribes killed the men and took the women. Then the only DNA evidence we might have today might be mitochondrial DNA besides the odd story ... or boat. Also possible those lines just died off. Disease could have easily wiped out entire family lines. Small pox pretty much wiped out a large part of many tribes. So we'd have to DNA test bones and not necessarily living people. An expensive endeavor so not likely to happen.
The show America Unearthed (airs on H2/History 2 and will premiere their new season shortly) has quite a few episodes that interlinks into the Welsh/Jewish discovery of America. Rather interesting show even if it's a bit ... tin-foil hat conspiracy at times. Granted, that's many shows on History anymore. Ancient Aliens, In Search of Aliens, etc. Everything's a conspiracy.

I watched the show when I caught the Meriwether Lewis episode
(since he's my cousin). I can certainly see a game with Connor and Meriwether Lewis. The guy's death was really strange.
It's pretty funny what we learn in school only to find out what really happened later. History gets really truncated in school, but that's not unexpected given budgets keep getting reduced and the number of kids keep going up. You can also only learn so much in a school year. Can't learn everything. Such a shame they teach a very poor version of history, though. By the time you get out of school, like half or better of what you learned of history is wrong in some way.
Only thing that's for certain is the native tribes were here first. So does it really matter who discovered the Americas? Columbus didn't. Leif Erikson didn't. The Welsh didn't. The Jews didn't. Funny how we want to say Europeans discovered America first when they didn't. Although now science seems to think there were two land routes: one from Asia over the Bering land bridge, and the other from Europe going east. The ice might have been so far south it created an ice bridge that lasted long enough for a few groups to travel across it. That would have let two groups settle in the Americas and branch out eventually joining in the middle.