Since 1860, Arlington National Cemetery has served as a final resting place for veterans from the U.S. and 11 other countries with over 420,000 buried within its confines. Nearly 5,000 unknown soldiers are buried throughout the cemetery and approximately 29 funerals take place every week. More than three million people visit Arlington National Cemetery each year to pay their respects.

In 1921, an unidentified American serviceman from World War I was brought back from France and interred at the Tomb of the Unknown Soldier; however, there was no monument at the time — it was just a stone that covered the opening of the tomb. In 1931, the marble monument that exists today was placed.

The Tomb of the Unknown Soldier, or Tomb of the Unknowns, contains the remains of soldiers from wars in which the U.S. has fought. More recent DNA testing has enabled the identification of remains and, in some cases, these have been returned to families for burial in their plots.