The town of Center was divided into Center, Spring Valley, Plymouth, Magnolia, etc., according to the government survey of townships.

The evidence

• “This town is situated on the west side of Rock prairie, and is mostly prairie Jand—the northern part oak openings and some very fine marsh for cutting grass. The following named persons settled in this town soon after Stevens: David Davis, Philander Davis, William Webb, William Warren, Elijah Wood, The town of Center, 18 miles east and west, nine miles north and south, including the present towns of Center, Plymouth, Spring Valley, south half of Magnolia, and that part of Janesville west of the river, was organized in 1842; and in 1846 was divided into Center, Spring Valley, Plymouth, Magnolia, &e., according to the government survey of townships.”

  1856-history-of-rock-county/08-center.md, PDF p. 95 / book p. 77

  Guernsey, Orrin, and Josiah F. Willard, editors. History of Rock County, and Transactions of the Rock County Agricultural Society and Mechanics' Institute. Janesville, Wis.: William M. Doty & Brother, 1856. Cornell University Library via the Internet Archive, archive.org/details/cu31924028871593.

  Grade A: Found on a page of one of our sources