Vermont was the first U.S. state admitted after the original Thirteen Colonies.
Congress admitted Vermont to the Union on March 4, 1791, after Vermont and New York settled a long-running territorial dispute. Vermont had declared independence from New York in 1777 and adopted its own constitution, but it remained outside the Confederation during the Revolutionary era because its status was contested.
The admission agreement required Vermont to pay New York $30,000 to resolve claims to the territory. After Congress approved the arrangement, Vermont became the fourteenth state. Its admission expanded the Union beyond the original thirteen states created by independence from Great Britain.
Kentucky became the fifteenth state later in 1792, followed by Tennessee in 1796. Vermont is therefore not one of the original thirteen, even though its early revolutionary history overlapped with theirs. Its constitution also contained an early prohibition on adult slavery, making it notable in the founding period.