So were Spanish fishermen. It is known that Basques fished off the Grand Banks millenia ago (and still do so today).
However, I don't think Spain could be responsible for the "Indian" ethnic groups. Basques are very tall and are the tallest men in Europe (oddly enough, the women are among the shortest), have very coarse black hair, and are extremely fair-skinned. I don't think you could find much in common with the average Algonquin.
Wow...that's something I didnt know. :D Thanks! YOu remind me of the Karankawa Indians, who lived mainly along the Texas coast and were known to be VERY tall and made tremendous long bows from a native tree, later dubbed "bois d'arc" or as I knew it "bohdark". These bows, it was said, were equivalent in strength and range to the English longbow and the Karankawa came to be known as cannibals through Cabeza de Vaca's reports.