1823 (about; the passage gives "about 1823 or 182J") — Thiebault, a French-Canadian trader, made his home at what is now Beloit.

The evidence

• “The first white person located at what is now Beloit, was one Thiebault (sometimes spelled Thicbeau, and pronounced Tebo),a French- Canadian trader, who must have made his home here about 1823 or 182J:, as according to his statement, made in 1836, he had gradually worked his way down from Green Bay to this locality some twelve years before, and had remained here trading with the Indians ever since. As the result of this trading, Thiebault, in 1835, claimed to be the owner of a vast tract of land extending for " three looks " in every direction from his cabin.”

  1879-history-of-rock-county/15-rock-county-ch09-beloit.md, PDF p. 603

  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