At the outbreak of the Civil War, Black men, both free and escaped slaves, immediately offered their services to the nation to participate as fighting men for a cause they understood would bring the evil institution of chattel slavery to an end in the United States.
All over the North they answered the call to arms issued by the government but were consistently denied the opportunity to serve. Abolitionists, both Black and White, launched a massive appeal to President Lincoln to allow those with the most at stake to don the Union blue. Frederick Douglass, Martin Delaney, Alfred M. Green, Charles Sumner, Thaddeus Stevens, Horace Greely, and many others gave rendering speeches, wrote stinging articles and did much more to convince Lincoln and Congress that the war was really more about ending the peculiar institution and less about states' rghts and saving the Union.
After much protest, an inferior military campaign, the emergence of the Radical Republicans and the disapproval and displeasure of the Northern citizens with the progress of Union war efforts, Congress began to take the steps to move forward in a new direction. Congress passed the Confiscation Acts of 1861 and 1862, which (1) declared all slaves found to be working for the Confederate war efforts as “confiscated property” and free, once under Union control, and (2) declared that the failure of Confederates, military and civilian, to surrender to Union forces within 60 days of the passage of the act (Second Confiscation Act) would have their slaves freed; and that all slaves taking refuge behind Union lines were free. Next, Congress passed the Militia Act of 1862 which permitted the use of Blacks as soldiers.
Unfortunately, they were only used as laborers to build fortifications, as messengers, cooks, nurses, and spies, but not as fighting men. It wasn’t until after the issuance of the Emancipation Proclamation, northern draft riots and the death of more than 50,000 Union forces at the Battles of Gettysburg and Antietam that Black troops began being used on the front line.
Famous Blacks in Arlington Cemetery [PDF]