Which U.S. State Borders Only One Other State by Land?

Quiz challenge

Which state borders exactly one other U.S. state by land?

A Vermont B Maine C Rhode Island D New Hampshire

Select an answer to continue.

Geography trivia often highlights extreme physical features, unique boundary lines, and curious spatial relationships across the fifty states. While several states are landlocked and surrounded by multiple neighbors, and island states are separated entirely by water, mainland state borders vary dramatically. Understanding how American internal boundaries were drawn during territorial expansion reveals surprising geometric and geographical quirks. One northeastern state stands out in particular for having the most exclusive land connection in the entire United States.

The correct answer

B) Maine

B) Maine is the correct choice. Maine shares a land border with only one other state in the nation: New Hampshire.

Maine is unique among all fifty U.S. states because it borders exactly one other state by land. Situated in the extreme northeastern corner of the contiguous United States, Maine is bordered to the west by New Hampshire. To its south and southeast lies the Atlantic Ocean, while its northern and eastern frontiers form an international border with two Canadian provinces, Quebec and New Brunswick. Because water and an international boundary enclose the rest of its land perimeter, no other U.S. state touches Maine. Hawaii has no land borders with any state, and Alaska borders Canada but no U.S. state, leaving Maine as the sole answer to this distinct spatial distinction.

Why each choice fits—or doesn’t

A) Vermont

Why it is not the answer: Vermont is incorrect because it shares land borders with three neighboring U.S. states. Vermont is bounded by New York to the west, Massachusetts to the south, and New Hampshire to the east along the Connecticut River. It also shares an international border with Canada to the north, but its three U.S. state borders disqualify it from being the single-border state.

B) Maine

Correct choice: Maine is correct because its internal U.S. terrestrial boundary is shared exclusively with New Hampshire. Running along Maine's Oxford and York counties opposite New Hampshire, this border is the state's only land link to the rest of the nation. Beyond New Hampshire, Maine's land perimeter touches only Canadian territory, making its single-state border a geographic distinction in American geography.

C) Rhode Island

Why it is not the answer: Rhode Island is incorrect because it borders two U.S. states by land: Connecticut to the west and Massachusetts to the north and east. In addition to its terrestrial borders, Rhode Island shares a maritime boundary with New York south of Long Island Sound. Even strictly counting land boundaries, Rhode Island touches two separate states, so it does not meet the criteria.

D) New Hampshire

Why it is not the answer: New Hampshire is incorrect because it touches three distinct U.S. states. Situated centrally in northern New England, New Hampshire shares land borders with Maine to its east, Massachusetts to its south, and Vermont to its west. It also shares a short international border with the Canadian province of Quebec along its northernmost tip.

More context

Maine's unique geographic position is rooted in colonial history and statehood politics. Originally part of the Commonwealth of Massachusetts, the District of Maine was physically separated from Massachusetts proper by New Hampshire. Following years of petitions for autonomy, Maine was admitted to the Union as the twenty-third state under the Missouri Compromise of 1820. Its northern and eastern borders with British North America were a source of tension during the nineteenth century, leading to border disputes like the bloodless Aroostook War. The international boundary was finalized by the Webster-Ashburton Treaty of 1842. Today, Maine remains the largest state in New England by total land area, yet its land entry point to the rest of the country remains through a single neighboring state.

Quick facts

Maine became the 23rd U.S. state on March 15, 1820, after separating from Massachusetts.
Maine shares international land borders with two Canadian provinces: Quebec and New Brunswick.
Alaska and Hawaii are the only two U.S. states that share land borders with zero other U.S. states.
The international boundary between Maine and Canada was officially established by the Webster-Ashburton Treaty of 1842.

Sources

Maine Guide to 2010 State and Local Census Geography — U.S. Census Bureau Maine’s only bordering U.S. state is New Hampshire.
Vermont Guide to 2010 State and Local Census Geography — U.S. Census Bureau Vermont shares land borders with Massachusetts, New Hampshire, and New York.
Seismicity Map of the State of Maine — U.S. Geological Survey Maine is bounded by New Hampshire to the west and Canada to the north and east.