A full honors funeral service passes in front of the Tomb of the Unknown Soldier at Arlington National Cemetery on its way to a gravesite. In March 1926, soldiers from nearby Fort Myer were first assigned to guard the Tomb of the Unknown Soldier. The guards, present only during daylight hours, discouraged visitors from climbing or stepping on the Tomb. In 1937, the guards became a 24/7 presence, standing watch over the Unknown Soldier at all times. The 3rd U.S. Infantry Regiment, known as “The Old Guard,” was designated as the Army’s official ceremonial unit on April 6, 1948. At that time, The Old Guard began guarding the Tomb of the Unknown Soldier. Soldiers of The Old Guard also serve as escorts to the president and conduct military ceremonies in and around Washington, D.C., including military funeral escorts at Arlington National Cemetery. Soldiers who volunteer to become Tomb Guards must undergo a strict selection process and intensive training. Each element of the Tomb Guard’s routine has meaning. The Guard marches 21 steps down the black mat behind the Tomb, turns and faces east for 21 seconds, turns and faces north for 21 seconds, and then takes 21 steps down the mat. Next, the Guard executes a sharp “shoulder-arms” movement to place his/her weapon on the shoulder closest to the visitors, signifying that he or she stands between the Tomb and any possible threat. The number 21 symbolizes the highest symbolic military honor that can be bestowed: the 21-gun salute.