Hanover is a small community in Sprague inside New London County, Connecticut. In the 2010 US Census the population was 67, but in 2014 the estimated population was 59. The main road, Hanover Rd., leads south to Route 138 and north to Route 14 in Scotland, while Salt Rock Rd. leads to Route 97. The Little River runs through the eastern part of th…Hanover is a small community in Sprague inside New London County, Connecticut. In the 2010 US Census the population was 67, but in 2014 the estimated population was 59. The main road, Hanover Rd., leads south to Route 138 and north to Route 14 in Scotland, while Salt Rock Rd. leads to Route 97. The Little River runs through the eastern part of the area. Hanover Reservoir is the largest body of water in the area. In the center of the village, some notably old houses are located there. Some are on the National Register of Historic Places. The ZIP Code for Hanover is 06350.