This is one of those goooood mysteries! So let's speculate and see what we come up with. Best I recall after all my long years in Yankeedom, Jefferson Cty. is Louisville, at one time the capital and the home of many antebellum and WBTS political and military powerhouses - Herschel Johnson and A. R. Wright foremost among them. A county like this would have well organized militia that might well have served in the Mexican War. A very political county like this probably would have used the opportunity to use that militia or its component parts to form Georgia Army or even early PACS units. Somewhere in the GA Archives there are probably muster rolls for the original militia Jefferson Rifles. I'd bet on a strong correlation between the officers and men of that unit to some or another early war Georgia Army or PACS unit. My Henderson's broken, but it looks like a good research project for someone with the time. Deo Vindice