From Wiki:
When the Michigan Territory was first established in 1805, it included only the Lower Peninsula and the eastern portion of the Upper Peninsula. In 1819 the territory was expanded to include the remainder of the Upper Peninsula, all of Wisconsin, and part of Minnesota (previously included in the Indiana and Illinois Territories). When Michigan was preparing for statehood in the 1830s, the boundaries proposed corresponded to the original territorial boundaries, with some proposals even leaving the Upper Peninsula out entirely. Meanwhile, the territory was involved in a border dispute with the state of Ohio in a conflict known as the Toledo War.
The people of Michigan approved a constitution in May 1835 and elected state officials in late autumn 1835. Although the state government was not yet recognized by the United States Congress, the territorial government effectively ceased to exist. A constitutional convention of the state legislature refused a compromise to accept the full Upper Peninsula in exchange for ceding the Toledo Strip to Ohio. A second convention, hastily convened by Governor Stevens Thomson Mason, consisting primarily of Mason supporters, agreed in December 1836 to accept the U.P. in exchange for the Toledo Strip.
