He remains the only president to come from New Hampshire. (If you don't count Jed Bartlet.)
He is the only president whose cabinet remained the same for his entire administration.
His vice president died after a few weeks in office, and was never replaced. The Senate majority leader was next in the succession line for the majority of his administration.
He was a long-time friend of Nathaniel Hawthorne, whom he appointed to a lucrative customs post.