Mars Hill was incorporated on February 21, 1867, from Mars Hill Plantation. The area was named by a British Army chaplain in 1790 who held a service on the Hill and likened it to the hill in Athens dedicated to Mars, where “the Apostle Paul declared the unknown God to the Athenians.” Later the British claimed the Hill defined the boundary between the United States and Canada. The Webster-Ashburton Treaty clarified the issue, placing the border much further north and the Hill, overlooking the St. John River valley, safely within the United States. — Maine, An Encyclopedia