In WWI, it was not so good (I realize that is a relative term.), but there were two black regiments from New York, who were not allowed to fight under "Black Jack" Pershing. They were assigned to the French, and acquitted themselves well. BTW, Pershing got his nickname from commanding troops in the 9th and 10th Cavalry.
The 24th Infantry was a black unit disbanded in Korea for alleged cowardice; a specious charge. My point is that it was not all one way or the other. Granted, "thousands" cannot be shown to be factual, except in the support roles we all know; but neither can it be shown that "no" blacks served in combat as Confderate soldiers. Stan