Answer: Maine

The majority of U.S. states are nestled in with other states, and even if they enjoy an expansive coastline (like California), they still rub shoulders with landlocked neighbors; then of course there are the states that share no borders at all with other states (island state Hawaii and far-north state Alaska with only a single international boundary with Canada).

The unique distinction of only bordering a single state, however, belongs to Maine. Located far up the East coast of the United States, Maine shares a single state border with New Hampshire. The rest of Maine’s borders are shared with the Canadian provinces of Quebec and New Brunswick, as well as the Atlantic Ocean.