Beginning with historian Helen Hornbeck Tanner in 1978, a number of historians have argued that Blue Jacket and Van Swearingen were not likely to be the same person. The historical record indicates that Blue Jacket was much older than Marmaduke Van Swearingen and was already an established chief by the time Van Swearingen was supposedly captured. Furthermore, no one who personally knew Blue Jacket left any records referring to him as a white man. According to Blue Jacket biographer John Sugden, Blue Jacket was undoubtedly a Shawnee by birth.