WASHINGTON (AP) — Honoring the legacy of John F. Kennedy, President Barack Obama laid a wreath at the assassinated president’s gravesite as a nation remembers that terrible day in Dallas a half-century ago Friday. Obama also recognized a group of distinguished Americans — including Bill Clinton and Oprah Winfrey — with the Presidential Medal of Freedom, an award created by Kennedy.Obama was joined at Arlington National Cemetery on Wednesday by Clinton, and each president held hands with Ethel Kennedy, widow of Robert F. Kennedy, as they climbed a flight of stairs to the burial site on a steep hillside overlooking the nation’s capital.Kennedy was killed by Lee Harvey Oswald in Dallas on Nov. 22, 1963, weeks before he was to honor the inaugural group of recipients with the Presidential Medal of Freedom. Hundreds of notable figures since have received the honor.Obama lionized the slain president Wednesday evening at a dinner at the Smithsonian’s National Museum of American History in honor of the medal’s recipients.