Why? They got there in ~6000 BCE, 8000 years ago.
If civilization got started in South America 5000 years ago, as it did in Egypt, India and China then what happened? Why did civilization advance in other parts of the world but not in South America or North America? Something does not compute.
"I am having a problem with the dates, 5,000 years is far to old."
Now I thought dating old hippies was pushing it, but you guys are saying 5000 years old is your limit? What, do you only go after the spry young 3000 year old ones?