During the colonial period, there were no wars expressly between separate colonies. However, there were a number of border conflicts, mostly involving New York. This occurred--most notably in the colonial period--in northern New Netherland (i.e., New York) over a contested border with Connecticut in the mid-seventeenth century, before the English took permanent control of the colony in the following decade. The conflict continued on-and-off for the rest of the century, even though the border was determined through an agreement in 1683 (and reinforced in 1700), though a distinct animosity between the two colonies continued. New York was also involved in disputes in the early seventeenth century over it's border with New Jersey.

In the middle of the eighteenth century, New York was again involved in border conflicts, this time with a group of renegades from New Hampshire led by Ethan Allen known as the Green Mountain Boys. They were contesting land known as the New Hampshire Grants that eventually became Vermont. In 1777, they declared Vermont to be an independent state and governed themselves as such until they were finally granted statehood in 1791.