By the end of the Civil War, roughly 179,000 Black men comprised 10 percent of the Union Army; and another 19,000 Black men served in the Navy. Yet, only one percent of the Northern population was African American. For these men it was a Holy War. They were the frontline forces in the final surrender of the Confederate capital. Read more.By the end of the Civil War, roughly 179,000 Black men comprised 10 percent of the Union Army; and another 19,000 Black men served in the Navy. Yet, only one percent of the Northern population was African American. For these men it was a Holy War. They were the frontline forces in the final surrender of the Confederate capital. Read more.