The point is really moot
Sure, I've read claims that some Chinese explorers might have beaten Columbus to America by 70 years or more. There are other credible claims that Vikings might have landed on our shores centuries before that.
In the end, the point is really moot. Whenever any of those explorers first stepped on our shores, they found people already living there. It seems kind of strange to go somewhere people have lived for thousands of years and then claim you discovered it.
