The Green Mountain Boys were a militia organization established in 1770 in the territory between the British provinces of New York and New Hampshire, known as the New Hampshire Grants and later in 1777 as the Vermont Republic. Headed by Ethan Allen and members of his extended family, it was instrumental in resisting New York's attempts to control the territory, over which it had won de jure control in a territorial dispute with New Hampshire.

The New Hampshire Grants or Benning Wentworth Grants were land grants made between 1749 and 1764 by the colonial governor of the Province of New Hampshire, Benning Wentworth. The land grants, totaling about 135, were made on land claimed by New Hampshire west of the Connecticut River, territory that was also claimed by the Province of New York. The resulting dispute led to the eventual establishment of the Vermont Republic, which later became the U.S. state of Vermont.