Question: This U.S. state's oldest school, Berwick Academy, overlooks the Salmon Falls River which forms part of the state border with New Hampshire. Name the state.
Sentence (from "Salmon Falls Mill Historic District"): They were built between about 1840 and the mid-1860s, and have an unusual architectural unity, for additions made to the buildings were done with attention to matching elements of the existing structures.
Relevant evidence: No