In 1747 an Ecclesiastical Society was formed in the area. From this Ecclesiastical Society the 15.7 sq mile town was established in 1848 from land acquired from both Hebron and Coventry.
Thus Andover became the 146th official town of the current 169 towns of The State of Connecticut.
Several small rivers and streams run through Andover, CT including Burnap Brook, Hop River and the Skungamaug River.
Nathan Hale State Forest is located in the southwest corner of the town. The Doris Chamberlain Nature preserve is located on Rte. 316 near School road and includes a small pond and walking trails.