WASHINGTON — Some arrived in the afternoon drizzle with the aid of canes. Others steadied themselves on the arms of spouses. But they displayed much of the same determination they had a half a century ago when they were the foot soldiers of President John F. Kennedy’s New Frontier.

A handful of surviving members of the 35th president’s White House staff came together Wednesday to relive heady times that have long since passed into American myth. They were invited for a private tour of the exhibit, “To The Brink: JFK and the Cuban Missile Crisis,” on display at the National Archives.