From everything I've read, Jesse and Frank were not leaders in the original gang. There is much speculation about exactly who was present at the first few Missouri robberies, from 1866-67, and no one will ever know for sure, but my thoughts are that Sheriff A.K. Reyburn of Ray County, MO got about as close as anyone did in the early days to figuring out who the original gang members were. He led a manhunt that lasted two years after the Richmond robbery of May 1867 and that eventually led to the demise of many of the original gang, including James Devers, Payne Jones, Dick Burns, Andy McGuire, Tom Little. These men made the mistake of staying in Missouri too long after the robbery. Devers was captured in Kentucky as the result of a double betrayal and was hanged with McGuire without benefit of a trial in Richmond.

I would certainly include George and Ol Shepherd as original gang members, Tom and Jim White, the Pence brothers, maybe Jim Cummins (on the fringe). There were most likely dozens who were original gang members and several men like Devers and the White brothers were several years older than Frank and Jesse and were shirt-tail relatives of the James boys as well.