Soldiers assigned to the 3rd Infantry Regiment, The Old Guard, conduct a change of guard at the Tomb of the Unknown at Arlington National Cemetery, Va., Nov. 15. Here, the soldiers port their arms during the ceremony. The Tomb of the Unknown has been guarded around the clock for more than three quarters of a century, specifically since 1937, and since 1948 by members of the 3rd Inf. Regiment's Old Guard regardless of the weather conditions. (National Guard photos by Staff Sgt. Joseph Rivera Rebolledo, Puerto Rico National Guard Public Affairs Office)