Inside Arlington Cemetery and standing on a hill overlooking D.C., the tomb was dedicated in 1921. It originally contained the remains of four unknown soldiers, each one representing the thousands of unknown soldiers from World War I, World War II, the Korean War, and Vietnam. Fortunately, in 1998, the unknown soldier from Vietnam was identified through DNA testing and was reinterred in St. Louis, Missouri.
Since 1948, elite soldiers from the 3rd Infantry Regiment of the U.S. Army (known as the "Old Guard") watch the tomb 24 hours a day, seven days a week, 365 days a year regardless of weather conditions. Sunshine, rain, snow, sleet, humidity, thunderstorms, heat, cold—they are out there! Each hour (in autumn and winter) and each half-hour (in spring and summer), see the changing of the guard ceremony with its special march and salute.