WASHINGTON — Britain’s Prince Harry saluted America’s war dead in somber remembrance at Arlington National Cemetery on Friday, pausing, too, to place flowers on the tombstone of John F. Kennedy and visit the grave of a British World War II hero buried far from home.There were none of the shrieking throngs that greeted his arrival Thursday on Capitol Hill at the opening of his weeklong U.S. visit, only solemn reflection at gravesites and time-honored ceremony at the Tomb of the Unknowns.Harry, a British Army captain who has served twice in Afghanistan, laid a wreath at the grave of another veteran of that war, Army soldier Michael L. Stansbery Jr., 21, of Mount Juliet, Tenn. He left a note reading: “To my comrades-in-arms of the United States of America, who have paid the ultimate sacrifice in the cause of freedom. Captain Harry Wales.”Stansbery, a Bronze Star and Purple Heart recipient, was killed July 30, 2010, by an improvised explosive device while on foot patrol in Afghanistan. His grave was chosen randomly for the prince’s honor, among thousands marking the resting places of the fallen from the Afghanistan and Iraq wars.Elizabeth Jennings of Arlington was in Section 60 tending to the grave of her brother-in-law and unaware that Prince Harry was just a few feet away until she was told. “I think it’s really great that he’s paying his respects,” said Jennings, whose brother-in-law Navy Lt. Cmdr. Jonas Kelsall was killed in Afghanistan in 2011. “They’re all brothers-in-arms.” Wearing his British Army uniform, Britain’s Prince Harry visits Friday with wounded warriors undergoing physical therapy at the Military Advanced Training Center at Walter Reed National Military Medical Center in Bethesda, Md., just outside Washington.