Actually, in 1864, a great many black soldiers saw action and died , most notably at Petersburg (in the Battle of the Crater), and at Fort Pillow, Tennessee and at Saltville, Virginia (where, in both cases, those that surrendered were massacred by their outraged Confederate captors). By the end of the Civil War, roughly 179,000 black men (10% of the Union Army) had served as soldiers in the U.S. Army and another 19,000 had served in the Navy. Nearly 40,000 black soldiers died over the course of the war-30,000 of infection or disease, and the rest in battle.
They volunteered to shoot Rebels, not get hurt!