Michigan assumed a State Government.

The evidence

• “Previous to the division and organization of Illinois Territory, the Territory of Michigan was organized from 'the northern part of Ohio Territory. In 1818, Illinois having formed a State Government, its northern portion, and what now constitutes Wisconsin, was attached to the Territory of Michigan, of which it remained a part until Michigan assumed a State Government, in 1835. At that time John S.”

  1856-history-of-rock-county/01-wisconsin.md, PDF p. 21 / book p. 3

  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