Dogs were in the Americas at least 10,000 years ago

"A trio of dogs buried at two ancient human sites in Illinois lived around 10,000 years ago, making them the oldest known domesticated canines in the Americas.

"Radiocarbon dating of the dogs’ bones shows they were 1,500 years older than thought, zooarchaeologist Angela Perri said April 13 at the annual meeting of the Society for American Archaeology. The previous age estimate was based on a radiocarbon analysis of burned wood found in one of the animals’ graves. Until now, nearly 9,300-year-old remains of dogs eaten by humans at a Texas site were the oldest physical evidence of American canines."

http://neveryetmelted.com/2018/04/19/oldest-american-domestic-dogs/