In 1850 census for Appomattox is the family of Nelson A. and Eliza O. Kelley. The eldest child was Martha C. Kelley, age 17.

About 1858, the family moved to Richmond. Martha does not appear with the family in 1860 and is presumed to have been married. No record of a marriage has been found, searching Richmond, Henrico and Appomattox (presumed lost in 1892).

Anyone with a record of a wife named Martha C., who might fit? Other reference?

While the marriage likely was in Appomattox (bride's residence), the groom could have been from Buckingham (where the family was in 1840) or Prince Edward (family there from late 1700s).