The changing of the guard at the Tomb of the Unknown Soldier in Arlington National Cemetery is an elaborate ritual. The guard is changed every hour on the hour between October 1st and March 1st. Between March and September, the guard changes every half hour.
Understandably, the requirements of the actual guards are similarly elaborate. The Tomb Guard sentinels are the best of the elite 3rd U.S. Infantry Regiment and are all volunteers. This regiment is headquartered at Fort Myer, VA. The sentinels must be in excellent physical condition, have an impeccable military record and stand between 5 foot 10 inches and 6 foot 4 inches tall with “proportionate weight and build.”
During their trial phase, the guards memorize 7 pages of Arlington National Cemetery history and the grave locations of nearly 300 veterans. They must recite this history exactly in order to earn the right to guard. If they do earn this right, they must continue training and serve for a trial period of a few months.