Vermont had operated as a sovereign republic since 1777, printing its own money and issuing its own citizenship. Its admission on March 4, 1791 marked the first expansion of the United States beyond the original colonies, setting a precedent for how new states would join the Union and easing tensions over New York's competing land claims.
For fourteen years, Vermont existed in a strange limbo: not a British colony, not one of the rebelling states, and not recognized by the fledgling United States government. It had its own constitution—the first in North America to ban adult slavery outright—its own currency, and its own postal service. New York claimed the territory too, a dispute rooted in colonial-era land grants that nearly triggered armed conflict between Vermont settlers and New York authorities.
The resolution came down to money and politics. Vermont agreed to pay New York $30,000 to settle competing land claims, clearing the last obstacle to statehood. Congress admitted it as the fourteenth state on March 4, 1791, deliberately balancing the admission of Kentucky (carved from Virginia) to preserve equilibrium between slave and free states—an early sign of the sectional arithmetic that would dominate American politics for the next seventy years.
Vermont's admission also mattered symbolically: it proved the Constitution's amendment and admission processes could function, and that the young republic could grow without simply subdividing existing states.