United States v. Lee (1882)
With local cemeteries in Alexandria County and Alexandria filling rapidly with war dead, Quartermaster General of the United States Army Montgomery C. Meigs proposed using of the Arlington estate as a cemetery. The first burial there was made on May 13, 1864. United States Secretary of War Edwin M. Stanton approved the establishment of a military cemetery on June 15, 1864, creating Arlington National Cemetery. By the end of the war in April 1865, more than 16,000 people had been buried at Arlington. In September 1866, a memorial and a burial vault (containing the remains of 2,111 U.S. and Confederate soldiers who died at the First Battle of Bull Run, Second Battle of Bull Run, and along the Rappahannock River) were buried in Lee's former wildflower garden on the mansion's east side beneath the Civil War Unknowns Monument, a memorial to honor unknown soldiers who had died during the American Civil War.
Abbey Mausoleum (Arlington County, Virginia)
Abbey Mausoleum was built in 1924 by the U.S. Mausoleum Company. The land was owned by the Syphax family. Maria Custis Syphax, the matriarch of the family, was the mulatto daughter of George Washington Parke Custis, grandson of Martha Washington and founder of the Arlington Estate on the banks of the Potomac River (later the home of Robert E. Lee). The Spyhax family sold the land to John Dormoyle in 1901, who then sold it to Frederick Rice in 1924. Rice subdivided the property into two lots, and sold one lot to the U.S. Mausoleum Corporation the same year. The lot was rectangular in shape and located next to the Hobson Gate.