Ground (ice) was broken for a flour-mill at the south end of the race at Janesville.

The evidence

• “Walker and Shubael W. Smith, to construct- a flour-mill at the south end of the race, on the site of the present post office, and on January 13, 1846, ground was broken for the work — or rather, we may say, ice was broken, for it was necessary to put in a cofier-dam, in order that the foundations might be laid, the site being almost entirely covered by the waters of the river. In the fall of the same year, six sets of stones were ready to revolve, and wheat-grinding commenced.”

  1879-history-of-rock-county/14-rock-county-ch08-janesville.md, PDF p. 557 / book p. 561

  Butterfield, C. W., et al. The History of Rock County, Wisconsin: its early settlement, growth, development, resources, etc. Chicago: Western Historical Company, 1879. Cornell University Library via the Internet Archive, archive.org/details/cu31924028871585.

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