An early popularizer of "Booth Escaped" theories was Finis L. Bates who claimed to have met Booth in Granbury, Texas in the 1870s and later to have taken possession of Booth's body after his suicide in Enid, Oklahoma in 1903. He toured the mummified body in carnival sideshows and wrote The Escape and Suicide of John Wilkes Booth (1908) in order to authenticate the mummy.
From Wikipedia...
An early popularizer of "Booth Escaped" theories was Finis L. Bates who claimed to have met Booth in Granbury, Texas in the 1870s and later to have taken possession of Booth's body after his suicide in Enid, Oklahoma in 1903. He toured the mummified body in carnival sideshows and wrote The Escape and Suicide of John Wilkes Booth (1908) in order to authenticate the mummy.