Winter 1837
Tebo/Thibault, the former and earliest proprietor of Beloit, was murdered, by his son Francis and his mother (one of his wives), after a family quarrel over whether to remain and cultivate the land or follow the Indians west of the Mississippi.
The evidence
“Tebo,) a Canadian, the former and earliest proprietor of Beloit, with his two Indian wives, resided near my claim, on what is now known as Thiebeau's point. He with his family—he had three or four children—remained here until the winter of 1837~38, when he was murdered, no doubt by his son Francis and his mother, one of his wives. This resulted from a family quarrel; he wishing to remain here and cultivate the land, they were anxious to follow the Indians west of the Mississippi.”
1856-history-of-rock-county/04-correspondence-pioneer-letters.md, PDF p. 60 / book p. 42
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
“Thiebeau, (pronounced Tebo), a Canadian, the former and earliest proprietor of Beloit, with his two Indian wives, resided near my claim, on what is now known as Thiebeau's Point. He, with his family (he had three or four children), remained here until the winter of 1837-38, when he was murdered, no doubt, by his son Francis and his mother — one of his wives. This resulted from a family quarrel, he wishing to remain here and cultivate the land ; they were anxious to follow the Indians west of the Mississippi.”
1879-history-of-rock-county/09-rock-county-ch03-pioneer-reminiscences.md, PDF p. 342 / book p. 346
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 · may repeat 1856-history-of-rock-county, so not counted as independent