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 Connecticut.

Several small rivers and streams flow through the town including, the Hop River, Burnap Brook, Staddle Brook, and the Skungamaug River. The Bear Swamp Brook runs through the Nathan Hale State Forest located in the northeast corner of town. The State owned Bishop's Conservation Area is located in the southwest corner of the town and includes the 53 ac. Bishop Swamp (Jurovaty) Pond. Andover Lake is a 155 ac. private lake in the southeast corner that provides recreational opportunities to its members.

 The Doris Chamberlain Nature preserve with small pond and walking trails is located on Route 316 near School Road.

Andover's rural character remains unspoiled with farmlands, stone walls and historic homes dotting the landscape. The original Town Hall of 1893 can be seen from Route 6 near the intersection with Route 316. The Old Town Hall now houses the town museum that is operated by the Historical Society. The new Town Office building is located on School Road between the town's firehouse and the elementary School.

Passing through Andover is the Hop River State Park Trail, a 6-mile gravel and compact earth trail that is part of the East Coast Greenway. It connects the Bolton portion of the trail way system with the Columbia portion at the town lines. It passes through Andover along Route 6, providing residents with opportunities for walking, bicycling and equestrian uses. The Veteran Memorial Field provides residents with recreational fields for baseball, softball, soccer and football events.

There is only one library, one church, one fire station and one school (K-6). The town is served by a regional middle and high school located in the neighboring town of Hebron.

Agricultural enterprises are visible in the form of beef cattle farms, horse farms, Christmas tree farms and garden shops.

Annual events include the Church Chicken B-B-Q, Firemen's Steak dinners, Library's Book and Bake sales, Church Country Fair, PTA's Breakfast with Santa, Easter Egg Hunt and Family Fun Day
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Three daily newspapers, (The Hartford Courant, The Willimantic Chronicle and the Manchester Journal Inquirer), one weekly newspaper (The Rivereast News Bulletin) and one quarterly publication (The Hometown News) cover local news and events in Andover