A, C, and D are the answers. Slaves all across the Union were freed by the 13th Amendment but those who sided with the Union gave theirs up first. The 54th Massachusetts was the most famous African-American regiment with all but their officers being freed slaves. Washington D.C., the nations capitol, used to reside in Virginia until the state sided with the Confederacy in 1860. Yet some counties refused to split, therefore creating West Virginia.