Dressed in the ceremonial uniform of his cavalry regiment – and the sky blue cap of the Army Air Corps – Harry, 28, first laid a wreath at Section 60, the area set aside for those who have died in Iraq and Afghanistan.
His message read: "To my comrades-in-arms of the United States of America, who have paid the ultimate sacrifice in the cause of freedom." He signed it captain Harry Wales.
After stopping by a memorial to President John F. Kennedy, Harry was escorted to the Tomb of the Unknown Solider.
As bright sunshine reflected off the white marble, he stood – amid 600 other spectators – in white gloved salute on the steps to hear the U.S. Army Band play the the national anthems of both the United States and the United Kingdom. Harry then stepped forward to place a wreath at the tomb.
During his eight days in the United States, Friday's solemn visit, which is to be followed by another to Walter Reed National Military Medical Center, Harry's presence was aimed at raising awareness of the needs of "wounded warriors" and their families.
Meanwhile, Thursday evening, Harry used the occasion of a dinner held by the U.K. ambassador to remember someone else: his mother Diana and her work with a landmine removal charity.
Harry, who's in the States for a week, also plans to visit Colorado, New Jersey and New York. His trip will end May 15 with a polo match in Greenwich, Conn., to aid his charity Sentebale.
Tim Rooke / REX USA