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.
Constitution Avenue
On March 4, 1913, Congress created the Arlington Memorial Bridge Commission (AMBC) whose purpose was to design and build a bridge somewhere in West Potomac Park which would link the city to Arlington National Cemetery. But Congress appropriated no money for the design or construction due to the onset of World War I. But after President Warren G. Harding was trapped in a three-hour traffic jam on the Highway Bridge while on his way to dedicate the Tomb of the Unknown Soldier on November 11, 1921, Harding began pushing Congress to move on constructing a new bridge. Congress approved funding for design work on June 12, 1922, and authorized construction of the Arlington Memorial Bridge on February 24, 1925.