SIR: Scouts from this post represent the enemy as having retired, they came to New Market Bridge on Wednesday, and left the next day. They -the enemy- talked of having 9,000 men. They were recalled by dispatches from Richmond. They had twenty pieces of artillery, among which was the Richmond Howitzer Battery, manned by Negroes. . . Their numbers are probably overrated; but with regard to their artillery, and its being manned in part by Negroes, I think the report is probably correct."
Federal Official Records, Series 1, Volume 4, "Report of Colonel John W. Phelps, First Vermont Infantry: CAMP BUTLER, Newport News, Va., August 11, 1861 – " p.569.
Phelps was a leading voice in the effort to allow Black men to fight in Union forces, including escaped slaves. This raised the ire of many in the South and in reaction the Confederacy would mandate execution for captured Black Union soldiers.
His grave can be seen here...