You'll probably need a good DNA test to see if there's any AmerIndian blood in your past.
http://freepages.genealogy.rootsweb.ancestry.com/~tynerdna/g... says DNA test results show that Dempsey is a descendant of Sarah Tyner/John Harris. There's no evidence whatsoever who his parents were, though. Since he's a descendant of Sarah and John, he is NOT Indian. Some of his descendants apply for Indian membership claiming he was a full-blooded Cherokee, some say their Tyner ancestors were NOT Indian and their membership comes through their mother. Bear in mind that many tribes didn't care about bloodlines; if you lived with the tribe, took part in tribal activities, and had family members who married in, you were a full member of the tribe. Very likely, when Dempsey rightly called himself a full Cherokee, his descendants remembered it as "full-blooded" and completely misunderstood.