This was territory of the Newichewannock Abenaki Indians, whose village was located on the Salmon Falls River. In 1668, Francis Small of Kittery, a trader, bought from Chief Captain Sunday (or Wesumbe) a large tract of land, for which he exchanged two blankets, two gallons of rum, two pounds of gunpowder, four pounds of musket balls and twenty strings of beads. Small thereupon sold half of his interest to Major Nicholas Shapleigh of Eliot, one of the wealthiest merchants in the Piscataqua region.

Settlement was delayed, however, by the ongoing French and Indian Wars, which finally ended with the 1763 Treaty of Paris. In 1773, the heirs of Francis Small and Nicholas Shapleigh promised a township to lawyer James Sullivan of Biddeford if he defended their larger claims. Sullivan accepted and in 1775 helped settle Limerick Plantation, named after Limerick in Ireland, his father's birthplace. It would be incorporated on March 6, 1787. Among the early settlers was Dr. Joshua Leavitt, for whom Leavitt Brook in Limerick is named. The town of New Limerick in Aroostook County would be settled by people from Limerick, Maine.

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