At least three.
Mid 19th c.
By the mid 19th c. the village of Hanover was the site of two woolen mills, these operated by the Allen Woolen Co. and the Washburn and Eaton Co. The Allen Woolen Co. mill was located in the vicinity of the eastern end of what is now Mill Street, while the Washburn and Eaton Co. mill was situated at the eastern end of what is now Mission Street. An 1868 map of the area identifies four residences owned by the Washburn and Eaton Co., these located along Main Street at the southeast corner of its intersection with Mission Street, and along the south side of Mission Street. Only one of these four buildings survive, this being the two-story wood-frame duplex located on Main Street south of Mission Street. The map identifies four residences and one boarding house associated with the Allen Woolen Co., all of these located along Mill Street immediately southwest of the mill. Two of these buildings survive at the present time. Several additional residences in the vicinity of the mill sites also appear to have served as employee housing, however, it is unclear which of the two mills they may have been associated with, or if they were built by the mill owners in the first place as they do not appear on the 1868 map. These consist of three two-story wood-frame duplexes located along the west side of Main Street between Salt Rock Road and Mission Street, three one-and-a-half-story wood-frame duplexes located along the east side of Main Street immediately north of Mill Street, as well as two one-and-a-half-story wood-frame duplexes located along the east side of Main Street a short distance north of Parkwood Road.