|President Ford and daughter Susan on the trampoline over Labor Day weekend - 1974|
newspaper story from 1967 describing a visit to Camp David by Australian Prime Minister Harold Holt and his wife in June of that year.
Mrs. Holt described President Johnson's daughter Lynda Bird as a "fantastic girl" who spent the weekend in the swimming pool and on the trampoline.
The only other trampoline information I found was about President Ford and his daughter Susan. They were photographed playing on the trampoline during a Labor Day weekend trip to Camp David in 1974.
According to this article, President Ford showed up at a meeting with National Security Advisor Brent Scowcroft with a bruise under his eye and told him he got it while jumping on the trampoline at Camp David.
Sources: Gerald R. Ford Presidential Library; The Age; History News Network