Duncan Gaines Cameron

If you didn't know already, I am a genealogy fanatic! I love nothing more than a lazy afternoon spent at the library or in a courthouse sifting through old records trying to flush out the branches of my family tree. This is most often a relaxing activity, although it can be interesting dealing with some of the area's older courthouses. Mold and mildew are a constant hazard.
Today. I spent several hours trying to research a particular interest of mine. He is my 3rd great-grandfather, Duncan Gaines Cameron. (That would make him my great-great-great grandfather, a gentleman five generations back.)
Old Duncan was born in Scotland in about 1785. The first definitive record I have of the man was the marriage banns (announcement of formal intent to marry) of his marriage in Orange County, N.C. on 5 May 1822. Before that, nothing.
A tailor by trade, Duncan received land in Franklin County, GA in the Cherokee Gold & Land Lotteries of 1827 and 1832. He is present on the 1830, 1840, and 1850 Censuses in the Carnesville District of Franklin County. The 1850 Census is of particular interest because it was the first one taken that required the enumerator to list the names of wives, children, slaves, or other family members.
One of the reasons I find Duncan to be so fascinating is that I have no idea what happened to him. The last incontrovertible record that I have been able to find was in 1864 where he was listed as next of kin on his daughter Theresa's commitment papers at the State Hospital in Milledgeville. She had been listed on the 1850 Census as being an idiot, probably either retarded or insane.
Otherwise, he and his surviving family just drops off the radar. He had lost all but one of his sons in the War Between the States. What money or property he and his family had possessed had been destroyed or taken from them. His daughter, my 2nd great-grandmother Sarah Elizabeth Cameron, was found as a servant in the household of Moses Keeling in 1860. Where did her family go? I wish I knew. I've looked.
I've recently come across records that state that Old Duncan was a soldier. If he had indeed been in the military, it must have been while he was still across the pond, because I have not been able to find any records of him serving in the War of 1812. The British Army was at the time embroiled in the Peninsula Campaign against Napoleon Bonaparte. Yet another reason I find my Cameron ancestor so fascinating.
I'm at a standstill when it comes to researching this man and his family. I've exhausted every avenue I can think of exploring. I suppose I'll either have to wait for new inspiration or just dumb fool luck. I think I'll hope for the latter.