In 1836 James T Watson, real estate agent from New York City, bought a large tract from the government that included all or parts of the present townships of Center, Plymouth, Magnolia, and Spring Valley. Because Mr. Watson was unmarried, the area was known as Bachelor's Grove. In the spring of 1841 David Douglas, Stephen C. Douglass and Samuel Colby who arrived with their families from Michigan on May 31st settled near one another on the banks of Bass Creek, near the present site of Hanover. Hanover, in the Town of Plymouth, at the junction of the Chicago, Milwaukee & St. Paul Railway and the Chicago & Northwestern Railway, was first located by Joseph Hohensheldt in 1844.
Town of Plymouth was organized by an act of Territorial Legislature on March 8, 1848 and the first town meeting of Plymouth was held on August 28, 1848. .The population of the Town of Plymouth in 1850 was 511. There were two railroad lines passing through the town, crossing at Hanover Station on Bass Creek.
In 1856 a post-office was established with William Ranney as the postmaster. The first freight was received at Hanover in Sept. 1857. The original name of Hanover was Bass Creek. It was changed by John Higgins, owner of the town site, to honor his German neighbors, some of whom had come from Hanover Township in NE Pennsylvania.
Source: Rock County, Wisconsin by William Fiske Brown and A. A. Jackson