The building of a dam above the town began to be seriously considered about 1843.

The evidence

• “But the building of a dam above the town was not seriously thought of until about the year 1843.”

  1856-history-of-rock-county/25-city-of-janesville.md, PDF p. 187 / book p. 169

  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