His son, John G Dunn died in 1885 so this may have lead to an error in the Memoirs of the Lower Ohio Valley.
His widow married Thomas Hargitt in Feb 1875.
Mr. Hargitt married a second time, the second wife being Mrs. Sarah E. Dunn, nee Sweet, a daughter of W. P. Sweet of Butler county, O., and the widow of Dr. John G. Dunn, who died in 1885.