Arlington National Cemetery

The 3rd U.S. Infantry Regiment began their rounds to place a small American flag into the ground in front of every grave marker at Arlington National Cemetery for the upcoming Memorial Day observance in 2008.

A rucksack filled with small American flags ready to place at gravesites. (Photo by Adam Skoczylas).

Master Sgt. Steven Colbert places a flag on a gravesite with his son's assistance. (Photo by Adam Skoczylas).

Flags stand vigil at gravesites in Arlington National Cemetary. (Photo by Adam Skoczylas).

The Tomb of the Unknowns at Arlington National Cemetery is also known as the Tomb of the Unknown Soldier. It stands on top of a hill overlooking Washington, D.C.

One of the more popular sites at the Cemetery, the tomb is made from Yule marble quarried in Colorado. It consists of seven pieces, with a total weight of 79 short tons (72 metric tons). The tomb was completed and opened to the public April 9, 1932, at a cost of $48,000.

It was initially named the "Tomb of the Unknown Soldier." Other unknown servicemen were later entombed there, and it became known as the "Tomb of the Unknowns", though it has never been officially named. The soldiers entombed there are:

Unknown Soldier of World War I, interred November 11, 1921.

Unknown Soldier of World War II, interred May 30, 1958.

Unknown Soldier of the Korean War, also interred May 30, 1958.

Unknown Soldier of the Vietnam War, interred May 28, 1984. The remains of the Vietnam Unknown were disinterred, under the authority of President Bill Clinton, on May 14, 1998, and were identified as those of Air Force 1st Lt. Michael J. Blassie, whose family had him reinterred near their home in St. Louis, Missouri.

The Tomb of the Unknowns is perpetually guarded by the U.S. Army. The 3rd U.S. Infantry Regiment ("The Old Guard") began guarding the Tomb April 6, 1948.