On Thursday afternoon, two days after the federal government released a trove of classified documents related to President John F. Kennedy’s assassination , tourists strolled leisurely on the incline between the Sixth Floor Museum and Dealey Plaza in downtown Dallas. Mike Sprecher, 66, had come here from Oregon. Sprecher was in kindergarten when JFK was assassinated and said it left an indelible memory. Visiting the place where JFK was shot and killed in his motorcade by Lee Harvey Oswald from the nearby book depository (now home to the Sixth Floor Museum) on Nov. 22, 1963 had been on Sprecher’s bucket...