Wallingford is a town in New Haven County, Connecticut, United States. The population was 45,135 at the 2010 census. The urban center of the town is delineated as the Wallingford Center census-designated place, with a 2010 population of 18,210. Wallingford was established on October 10, 1667, when the Connecticut General Assembly authorized the "making of a village on the east river" to thirty-eight planters and freemen. The "long highway" located on the ridge of the hill above the sandy plain along the Quinnipiac River is the present Main Street in Wallingford. On May 12, 1670, Wallingford was incorporated and about 126 people settled in the town. Six acre lots were set out and by the year 1675 forty houses stretched along today's Main Street. In 1775 and again in 1789, George Washington passed through Wallingford.