The gang originated in Oklahoma, following the downfall of the Wild Bunch at the hands of three Deputy US Marshals, Heck Thomas, Bill Tilghman, and Chris Madsen.
Following the killing of outlaw and Wild Bunch leader Bill Doolin, by Heck Thomas in 1896, "Little Dick" West joined up with Al and Frank Jennings, and Morris and Pat O'Malley, to form what would be known as the Jennings Gang.
Al and Frank Jennings, as well as both O'Malley brothers, were captured and sentenced to prison.
"Little Dick" West eluded capture until later in 1898, when he was killed by Deputy US Marshal Madsen, in Oklahoma.
In 1914 Al Jennings ran for Oklahoma Governor, but was soundly defeated.