[1][2] An Order-in-Council signed by King George III on July 20, 1764, said that the boundary between New Hampshire and New York is the west bank of the river.

The order was intended to settle a dispute between New York and New Hampshire in which each claimed the territory that later became the state of Vermont.

The disputed territory had been governed for 15 years as a de facto part of New Hampshire, but the king's order awarded it to New York.

On August 20 and 21, 1781, Congress expressed conditions that must be met before the then-still unrecognized but de facto independent state could be admitted into the Union.

In order to assure compliance with the Supreme Court's ruling, in 1935 the legislatures of Vermont and New Hampshire enacted laws requiring the attorneys general of those two states to meet at the river once every seven years to reaffirm their mutual understanding of the location of the boundary.