Twenty years ago, most archaeologists believed the first Americans were not fishermen, but rather big-game hunters who had followed mammoths and bison through the ice-free corridor in Canada. The distinctive Clovis spear points found at sites in the lower 48 states starting about 13,500 years ago were thought to be their signature. But bit by bit, the Clovis-first picture has crumbled. The biggest blow came in 1997, when archaeologists confirmed that an inland site at Monte Verde in Chile was at least 14,500 years old—1000 years before Clovis tools appeared. Since then, several more pre-Clovis sites have come to light, and the most recent date from Monte Verde stretches back to 18,500 years ago, although not all researchers accept it. Genetic evidence from precontact South American skeletons now suggests that the earliest Americans expanded out of Beringia about 16,000 years ago.

 https://www.science.org/news/2017/08/most-archaeologists-think-first-americans-arrived-boat-now-they-re-beginning-prove-it