ARLINGTON, Va. -- The Tomb of the Unknown Soldier is an eternal salute to unidentified American war dead.
Guarded around-the-clock by heel-clicking Army sentries, the monument stands in Arlington National Cemetery -- high above seemingly endless rows of military tombstones and across the Potomac River from the nation's capital.
It is inscribed with the words, 'Here rests in honored glory an American soldier known but to God.'
Congress authorized the white marble Tomb on March 4, 1920 - following a European custom of erecting monuments to unknown war dead.
An unknown American soldier of World War I was entombed on Nov. 11, 1921 in ceremonies attended by President Warren G. Harding, who conferred the Medal of Honor, the nation's highest military award, on the fallen warrior.
President Dwight David Eisenhower officiated on May 30, 1958 - Memorial Day -- when unknown soldiers from World War II and the Korean War were buried to the right and left of the Tomb, respectively.
Eisenhower placed the Medal of Honor upon the crypt of each soldier.
Congress in 1973 ordered the burial of an unknown soldier from Vietnam. But it took the military until this year to come across remains it was unable to identify.
The Tomb of the Unknown Soldier is guarded by selected members of the Army's 3rd U.S. Infantry. The monument is among the area's most popular tourist attractions, drawing about 3.5 million visitors a year.
Arlington National Cemetery, established on June 15, 1864, is administered by the Army Department.
As of April 30, there were a total of 189,286 interments at the cemetery, including 4,724 who are unknown soldiers.
