I researched him for 9 years (no relation). the Cecil county historical society has a copy of his war diary. It includes - in his writing - accounts of several events, including letters to sarah and mentions his son Johnny. In the Ky historical society [probably by accident] I found a long didtance photo of sarah and william on their front porch.
John was an attorney - during the war he wore a full beard and wore his hat with the brim down all around.

good luck.

Gary