Edward G. Longacre, "Pemberton, John Clifford," American National Biography Online, February 2000, http://www.anb.org/articles/05/05-00068.html.
Long in favor of enlisting African Americans, Birney supervised the recruiting of the U.S. Colored Troops (USCTs) early in 1863. With characteristic energy, he personally raised seven regiments composed of black residents of Maryland, including the inmates of slave prisons he liberated. On 22 May Birney was appointed a brigadier general of volunteers. In this capacity he was able to fulfill an oft-stated desire "to give the colored troops a fair chance of distinction in the field." He was assigned a brigade of USCTs in the Department of the South, which he commanded at Beaufort, South Carolina, and later at Jacksonville, Florida. In both locales he protected government property and Unionist citizens while conducting limited offensives with white soldiers as well as Colored Troops. His preference for the latter, however, was never in doubt; on at least one occasion he offered to trade white units for an equal numbered of USCTs.