Article and photograph here... http://www.theguardian.com/science/2015/jan/26/dogs-dna-ancient-humans-americas Interesting.
Dogs were first domesticated here by the American Indians long before they were brought here by the early colonists. When Europeans first arrived here dogs were already being used by the Indians for a host of different things. Of course, no one knows when or where the first Indians came from. Most of the tribal histories say they "came from the sky" in one way or another. There are ancient cave drawings throughout the USA depicting dogs sharing in the daily lives of their American Indian companions.