�–� Nov. 11, 1921, the Tomb of the Unknown Soldier is dedicated. Four unknowns were exhumed from four different American cemeteries in France. Caskets were shifted and rotated, with no trace remaining of which cemetery each had come from. A sergeant who had not been present for the moving of the caskets was led into a room and randomly placed white roses on one of the caskets to select one soldier for the World War I Tomb of the Unknown. In this manner, the unknown truly represented any man, and could have been any mother’s son. It was for this purpose, to give comfort to families of the fallen, that the Tomb of the Unknown was created.

�–� May 30, 1958, President Dwight Eisenhower presides over the dedication as unknown soldiers from World War II and Korea come to rest alongside the World War I unknown.

�–� Great care is taken again to find a truly unknown soldier from World War II, drawing the remains of 18 fallen soldiers from virtually every theater of battle. Similar techniques of swapping around caskets to disguise its source were used to select one soldier for burial at the Tomb of the Unknown.

�–� To locate an unknown from Korea, four unidentified remains were exhumed from the National Memorial Cemetery (Punch Bowl) in Hawaii. Again, the caskets were moved around to make sure the final selection was completely unknown.

�–� May 28, 1984, seeking to finally give Vietnam veterans more of the respect they so richly deserved, President Ronald Reagan delivers remarks as an unknown soldier from Vietnam joins the ranks at Arlington’s Tomb of the Unknown. Few could have then imagined the advances in DNA that would eventually see this soldier identified.

�–�On May 11, 1988, Lt. Michael J. Blassie, the former unknown, was laid to rest at Jefferson Barracks National Cemetery, MO., at the request of his family.

�–� Sept. 11, 2001, Arlington National Cemetery is basically across the street from the Pentagon. Tomb guards could almost feel the blast when terrorists crashed American Airlines Flight 77 into the Pentagon at 9:37 a.m. Despite the chaos that ensued, the Tomb was never unguarded. At 1030 hours, Arlington was closed to the public. Tomb guards changed out of their dress uniforms, put on BDUs (battle uniforms), and continued their watch, according to tombguard.org.