During February 1864, the Adjutant General of the U.S. Army, Lorenzo Thomas, under the direction of the Secretary of War, Edwin L. Stanton, authorized the recruitment of African Americans by the Union Army in Kentucky. The 8th United States Heavy Artillery (Colored) was one of these units. It was largely recruited in the Paducah area and headquartered at Fort Anderson throughout the War.
By the middle of March 1864, 274 men had enlisted in what was then designated as the First Kentucky Heavy Artillery, African Descent. Lieutenant R.D. Cunningham was in charge of recruiting troops and training them to operate the artillery at Fort Anderson and also as infantrymen.
Each state, including Kentucky, had quotas for enlisting African Americans. Because many people had crossed statelines when leaving slavery behind there was confusion as to what state they were from and which state should receive credit. The various African American units were re-designated as United States Colored Troops and the First KY Heavy Artillery, African Descent became the 7th United States Heavy Artillery (Colored) and finally the 8th United States Heavy Artillery (Colored).
On March 25, 1864 the Eighth formed a major part of the garrison of Fort Anderson with 120 men from the 122nd Illinois Infantry and 271 from the 16th Kentucky Cavalry. The fort was commanded by Colonel Stephen G. Hicks. In addition, two federal gunboats, the Peosta and the Pawpaw, on the Ohio River, supported Hick's command. During the Battle of Paducah on that day the Eighth fought well. Hicks, who had been opposed to the enlistment of African Americans, compared their conduct in combat favorably to the best troops he had fought with during the War.
The Eighth actively recruited throughout the War and by May 1864 was at 317 men, commanded by Colonel Henry T. Barry. When the unit joined the 132nd Illinois Infantry on an expedition to investigate reported Confederate activity near Haddix's Ferry on July 27, 1864 400 men from the Eighth took part along with 200 from the Illinois unit. A similar mission in August led to small skirmish near Smithland, Kentucky.At the end of the War in April 1865 the Eighth was transferred to Texas where it remained until mustered out of federal service on February 10, 1866.