The Meadowcroft site, near Pittsburgh, dates back some 19,000 years.
Cactus Hill, Virginia and Topper, SC as well. All seem to be on the East coast of North America, just where the glaciers ended and at the most southern limit of sea ice in the Atlantic during the last major glaciation. Sea ice that extended in an arc across the Atlantic to France and Spain.
The sea level was 300 feet lower then, so much more land OFF the US East Coast and France/Spain West coast.
Image humans in France going out to sea to catch seals and fish in skin hide boats, following the sea ice edge... And, either inadvertently or in a storm — reaching the American coast. Perhaps there were even waves of such voyages.