They began interring Federal dead on the grounds of Robert E. Lee's plantation, named Arlington, that he had inherited from his wife, who descended from Martha Washington and her first husband. The Federal government perceived this as a way to punish Lee for siding with the Confederacy, after being offered command of the Union army and turning it down. So graves first found a place at Arlington about 1862 or 63, during the opening years of the Civil War.
Arlington National Cemetery officially became a national cemetery June 15, 1864. The first service member to be laid to rest here was Pvt. William Christman, May 13, 1864.
Thanks! Your answer is awaiting moderation.