Kevin Clark / The Washington Post / Getty ImagesIn 2008 Allen told then-Washington Post writer Wil Haygood, who later wrote the book on his life, that he had shaken hands with every president whose administration he had worked for-- from Truman to Reagan. Allen kept a couple of mementos along the way including Lyndon Johnson’s hat, 10-karat gold presidential cuff links, and pens. First Lady Jacqueline Kennedy, Allen said, gave him one of President Kennedy’s ties the day of his funeral. Allen was in the White House the day Kennedy was shot and the day of the funeral. Though invited to attend, he decided to stay back and prepare to serve the Kennedy family when they returned from the services.