A Hawke

Some years back in the course of work I met a man whose family name was Hawke. When our business was completed I asked him, if he were related in some way to Horatio Hawke the distinguished British naval officer of the early 19th century. Mr. Hawke responded in the negative and told me that the name was that of his paternal grandfather, a Native American. I was puzzled and asked about the final 'e'. He answered that his grandfather had added the 'e' in the belief that this would make his name more American.