He enlisted at the age of 21 in the 34th United States Colored Troops Infantry Regiment on January 19, 1865, at Camp Casey, Virginia, for a period of three years. He mustered into Company B as a private the next day, and his service records describe him as 5 feet, 7 inches tall, with black hair and eyes and a brown complexion. Upon being mustered in, the regiment was in the process of transferring to the 4th Separate Brigade, District of Florida in the Departments of the South and the Department of Florida. Clay was transferred to Jacksonville, Florida, for duty throughout that state. Upon his arrival in Florida, Clay, perhaps unaccustomed to the hot Florida summer, developed sun stroke, and died in the regimental hospital in Jacksonville on July 7, 1865. No pension was ever filed by surviving family members.
Private Clay was profiled by the University of Virginia's John L. Nau III Center for Civil War History in 2017, as part of their "Black Virginians in Blue" digital project.
- Web. [ Henry Clay (34th USCT)], Website, John L. Nau III Center for Civil War History: Black Virginians in Blue, April 10, 2021, retrieved July 28, 2021.