The 12th Regiment, United States Colored Heavy Artillery was organized & formed at Camp Nelson, Kentucky, on 15 July, 1864. The Regiment was assigned to the 2nd Brigade, 1st Division, District of Kentucky, Department of the Ohio. In January, 1865, It was officially assigned to the Military Department of Kentucky. The Regiment served garrison duties in Bowling Green, Camp Nelson, & other locales in Kentucky. The Regiment was mustered out of Federal service on 4 April, 1866.