“As you lay your flower, we at Arlington encourage you to reflect on the meaning of the Tomb. The Tomb of the Unknown Soldier has been a final resting place for three unknown US service members, beginning in 1921, but has also served as a symbolic grave for unidentified or unlocated American solders. “The next two days will truly be a historic and once-in-a-lifetime opportunity,” she said Tuesday morning, kicking off the start of the Tomb’s two-day flower ceremony. People place flowers during a centennial commemoration event at the Tomb of the Unknown Soldier, in Arlington National Cemetery in Arlington, Virginia on November 9, 2021.