November 11, 2021 marked the 100th anniversary of the dedication of the Tomb of the Unknown Soldier, the most visited site in Arlington Cemetery. 

The first unknown soldier from World War I was honored on Armistice Day in November 1921. The body lay in state in the U.S. Capitol rotunda where 90,000 people viewed the casket. On the following day, a caisson transported the unknown soldier to Arlington National Cemetery. During the procession, the casket was escorted by members of the military, President and Mrs. Warren G. Harding, Vice President and Mrs. Coolidge, Chief Justice Taft, and the remaining justices of the Supreme Court. Members of the Cabinet, Senate, and House, along with several hand-picked Generals, were also on hand to witness the presenting of the Medal of Honor and the Distinguished Service Cross to the unknown dead. 

The Tomb we see today was completed and put in place without a formal ceremony on April 9, 1932. 

In 1958 unknown soldiers from both the European and the Pacific war theaters of WWII, and the Korean War were interred at the Tomb as a result of a law signed by President Eisenhower. 

Modern science allowed the eventual identification of the Vietnam Unknown Soldier. The military decided that the crypt that contained the remains of the Vietnam Unknown will remain vacant. The crypt cover has been replaced with one that has the inscription, “Honoring and Keeping Faith with America’s Missing Servicemen, 1958-1975.” 

Arlington National Cemetery also has the Tomb of the Civil War Unknowns, which holds the remains of 2,111 unidentified Civil War soldiers. 

There are over 4,000 other unknowns buried at Arlington National Cemetery, from the Civil War through the 20th century. 

The Army 3rd Infantry Regiment is entrusted with tending to and guarding the Tomb of the Unknown Soldier. The unit also coordinates all burials that take place in Arlington National Cemetery.  

The unit is known informally as the ‘Old Guard.’ The select few who become Tomb Sentinels perform the responsibility with the utmost precision and grace.  

Since April 6, 1948, the Tomb of the Unknown Soldier has been guarded 24/7. The guards change every hour from October through March and every half hour from April through September. 

Visitors from all over the world travel to Arlington National Cemetery to pay their respects and to witness the iconic changing of the guard.