David and William Birney — sons of the Bay City abolitionist — were major generals, recruiting and leading colored troops. And James G. Birney IV, grandson, enlisted in Bay City and rode with Gen. Custer in the Michigan Cavalry Brigade that stopped the rebel cavalry under Gen. J.E.B. Stuart and helped the North win the crucial Battle of Gettysburg.
On April 8, 1865, Gen. William Birney and his black troops trapped the remnants of Robert E. Lee’s Army of Northern Virginia as they neared Appomattox. Because he was halted and relieved of duty by Maj. Gen. E.O.C. Ord, Birney was denied the honor of capturing Lee and ending the war that day. Instead, Lee and his men were allowed to escape and fight another day. After another futile rebel attack costing about 600 lives, Lee finally was forced to surrender on April 9.
Source : Dave Rogers, “Black Diamonds: Talk Eyes Area Blacks in Civil War, More History Notables“, MyBayCity.com, February 20, 2015.