In Washington service members honored those buried at Arlington National Cemetery.
    
They placed United States flags on each of the more than 300,000 graves.
    
This has been a Memorial Day tradition since 1948 conducted by the soldiers from the third U.S. infantry regiment, known as the Old Guard.
    
They were joined by selected personnel from the other military branches.
   
Each flag was reverantly placed one foot from the marker and fallen medal of honor winners were given a respectful salute.
    
The Old Guard will stand watch over the flags through the entire weekend.