August 25, 1828
The United States made a treaty at Green Bay with the Winnebago and other tribes, to remove difficulties arising from white occupation of the unceded mining country of southwestern Wisconsin.
The evidence
“10. A treaty was made at Green Bay, August 25, 1828, with the Winnebagoes, Pottawattamies and other tribes. This treaty was made to remove the difficulties which had arisen in consequence of the occupation by white men of that portion of the mining country in the southwestern part of Wisconsin which had not been ceded to the United States.”
1879-history-of-rock-county/04-wisconsin-railroads-commerce-health-statistics.md, PDF p. 211 / book p. 216
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
“But during the year 1827 mining at Fever river, Illinois, was extended into the Winnebago country and caused an Indian uprising that year. In 1828 Colonel Henry Dodge and 130 men were digging ore thirty miles within Wisconsin lands, removing the ore across the line by night. The Indians discovered and resented this. More troops having been sent, the result Avas the Winnebago war between Colonel Dodge and Chief Red Bird, the latter nobly giving himself up to death as a sacrifice for his people. August 25, 1828, the United States, by Lewis Cass and Pierre Minard, at Green bay, made a provisional treat}' with the Winnebago, Chippewa, Ottawa and Pottawattomie Indians, the latter having only "squatter's rights," for lands which were permanently ceded later. Then, by our eighth treaty, made at Prairie du Chien, July 29, 1829, the Chippewas, Ottawas and Pottawattomics ceded to the United States all their land south of the Wisconsin river and covered by the Sac and Fox cession of 1804, including therefore the lead regions and also the whole of this county. By the treaty of August 1, 1829, Winnebagoes ceded the lead regions. It is said that the lead fever of 1828 was like the gold fever of ”
1908-brown-rock-county/02-ancient-occupants.md, Vol. 1, PDF p. 39 / book p. 31
Brown, William Fiske, editor. Rock County, Wisconsin: A New History of Its Cities, Villages, Towns, Citizens and Varied Interests, from the Earliest Times, Up to Date. Chicago: C. F. Cooper & Co., 1908. 2 vols. archive.org/details/rockcountywiscon01brow, archive.org/details/rockcountywiscon02brow.
Grade A: Found on a page of one of our sources