John F. Kennedy did not even reach a full three years in office before he was murdered.
A lot of work he intended to do never got done. Or it got done by other people.
This is the argument Andrew Cohen makes in his book Two Days in June: John F. Kennedy and the 48 Hours that Made History.
Cohen recounts the story of speeches Kennedy gave on consecutive days in June 1963 that led to major pieces of legislation. The author visited in early 2015, and we hear his words again here.