U.S. Grant made a serious bid for a third term in 1876, four years after leaving the White House, but couldn’t secure the nomination even after 36 ballots: Ulysses S. Grant - Wikipedia
Garfield is the only sitting house member to be elected president and he only served 6 months because he was murdered.
Yes. Garfield was also elected to the U.S. Senate in 1880, but never took his seat: James A. Garfield - Wikipedia
Rep. Matt Santos (D-Texas) on The West Wing became only the second House member elected directly to the Presidency.
Words written on many a gravestone, to be sure.