Union is a town located in the northeastern part of Tolland County, Connecticut, United States and is part of the Northeastern Connecticut Planning Region and Last Green Valley National Heritage Corridor.

[1] Union includes the village of Mashapaug located in the Eastern Uplands at the Massachusetts state line.

Union is located 33 miles (53 kilometers) northeast of the state capital, Hartford and 67 mi (108 km) southwest of Boston, as well as 153 mi (246 km) northeast of New York City.

They are a member of the Nipmuck District and chartered by the Union Volunteer Fire Department.

[8] The highest elevation in eastern Connecticut is 1,315 feet (401 m) Burley Hill in the northwestern part of town.

With over 40,000 acres of forestland in and around town and a major interstate going through it, Union is known for outdoor recreation such as hunting, fishing, hiking, camping and picnicking.

[14] Most activity is centered on Bigelow Hollow State Park, and especially at Mashapaug Lake.

[15] The village of Mashapaug in Union is the site of the Traveler Restaurant, a unique eating establishment that gives away used books to its patrons.

The camp was originally situated on Lake Zoar in Monroe, but was relocated to the Union property when the original camp's dining hall was destroyed by a severe winter storm.

The camp includes old stone foundations of the buildings once comprising Well's Mill, and also includes a small Revolutionary War cemetery where, among other soldiers interred, lies a brother-in-law of Benedict Arnold.

The library was established by a town meeting in November 1894, and opened March 25, 1895, in a private home.