Well Bobbie the first issue is name and location. Guesstimates range from 10,000 to 30,000 Missouri males would have fit the "Billy the Bushwacker" moniker during the period of 1861-1865. Of those I can pretty well say there were hundreds of folks named William. So if you have a first name, last name, and estimate of date of birth we may be able to help you. Even the name of the town he holed up in would be helpful as it may lead to the discovery of a particular unit he was involved with. Thanks we'll be happy to help but need some more specifics.