William Rufus DeVane King was the long time room mate (in Washington, DC) of later President James Buchanan. At that time Congress was in session for only a few months every other year, the rest of the time they were in Alabama and Pennsylvania respectively. King was elected VP with Pierce in 1852, but took the oath of office in Cuba where he was staying for health reasons (it took a special act of Congress to allow this). He died at home shortly afterwards, and never set foot in DC while he was VP.
There were whispers that King and Buchanan were more than just roommates.