My great grandfather changed his name to Charles E Holmes during or right after the Civil War (he was in the Illinois Infantry). I just now learned what his name was prior to that: Charles C Erichson. He reported that he and both parents were born in Denmark, but that is all we know. I'm hoping to find other Erichsons from Denmark who may have immigrated around the same time (1860) or for any other connections.
Our y-DNA Haplogroup is N1c1, more characteristic of northern Scandinavia, not so common in Denmark it seems.