The correlation is striking. I really don't know if the Kennewick has something to do wih it but it was found on the North Western coast of the USA.
First, it was believed that the shape of his skull was caucasian but now it is believed that the Ainu of japan share the most similarities with the Kennewick man. The latter is beween 12 000 and 7500 years old. It fits well with the Jommon period. The problem is that almost all Ainu people carry D Haplogroup (with a small minority of C) and D isn't found in Amerixa so far.