Well, I have a great grandfather names James I Jackson buried in Mt. Olivet cemetery in McKenzie, TN. Supposedly he was a 2nd lieutenant and born in Granville, NC, on Dec 11, 1854, and died on Jun 9, 1898, in McKenzie. Records show that he married Pattie H. Henderson in 1883 when he was 52.
Do you think he's the same person you're looking for?