<P> On March 4 , 1921 , the United States Congress approved the burial of an unidentified American serviceman from World War I in the plaza of the new Memorial Amphitheater . On November 11 , 1921 , the unknown soldier brought back from France was interred below a three - level marble tomb . The bottom two levels are six marble sections each and the top at least nine blocks with a rectangular opening in the center of each level through which the unknown remains were placed through the tomb and into the ground below . A stone , rather than marble , slab covers the rectangular opening . </P>
<P> On March 4 , 1921 , the United States Congress approved the burial of an unidentified American serviceman from World War I in the plaza of the new Memorial Amphitheater . On November 11 , 1921 , the unknown soldier brought back from France was interred below a three - level marble tomb . The bottom two levels are six marble sections each and the top at least nine blocks with a rectangular opening in the center of each level through which the unknown remains were placed through the tomb and into the ground below . A stone , rather than marble , slab covers the rectangular opening . </P>
when did the tomb of the unknown soldier start
when did the tomb of the unknown soldier start
March 4 , 1921
March 4 , 1921