From NKAA, Notable Kentucky African Americans Database (PIONEERS & PATRIOTS: Anderson County Military Servicemen, Revolutionary War - WWI)

Franklin was born a slave in Anderson County about 1838. He remained a slave into adulthood; President Lincoln's Emancipation Proclamation only freed slaves in states openly hostile toward the Union. Late in the war, however, the government called for the enlistment of colored regiments, and all who answered the call were granted immediate freedom.

One of those who chose to become a soldier was Mark Franklin, who made his way to Camp Nelson to enlist; on July 22, 1864 he was enrolled as a private  and later corporal in Company C of the 12th U.S. Colored Heavy Artillery Regiment.

The 12th Artillery saw no reported action, mainly serving garrison duty at various locations throughout Kentucky until it was discharged from service on April 24, 1866.