 Although US 4 does come close to the Maine border, the intended connection never came to fruition, as US 4 was routed south of Dover to terminate in Portsmouth.Instead, an indirect connection exists, facilitated by NH 4, NH 9, and NH 16 (the Spaulding Turnpike).As first designated in 1931, SR 4 extended from its current southern terminus in South Berwick all the way to the Canada–US border.