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.
Arlington National Cemetery
On July 12, 1999, the NPS issued a Federal Register notice that announced the availability of an environmental assessment (EA) for the transfer. The EA stated that the Interment Zone contained the oldest and largest tract of climax eastern hardwood forest in Arlington County. This forest was the same type that once covered the Arlington estate, and had regenerated from trees that were present historically. A forestry study determined that a representative tree was 258 years old. The Interment Zone was also determined to contain significant archeological and cultural landscape resources, in addition to those in the Preservation Zone. The EA described four alternative courses of action.