The Clovis point people, originally discovered in Clovis, NM, are one of the early peoples nobody can agree upon. Some scientists prefer to think of them as a purely American people, some say the first American people. But there's evidence in Oregon for an older people, and there's evidence pointing to the origins of the Clovis people as coming from France.

The Atlantic was smaller at that time, since it's been widening at about 1 1/2" per year since that time. Ocean levels were probably a bit lower then too. So crossing the ocean wouldn't be the daunting task it is today. It's not as outrageous an idea as some scientists suppose.

But since that was over 20,000 years ago, it's kind of hard to tell.