Wayne County, Michigan, originally part of the vast Northwest Territory, was eventually whittled down into its current size by the separation of several tracts: Monroe in 1817, Michilimackinac County (later called Mackinac) and Macomb counties in 1818, St. Clair and St. Joseph counties in 1820 and Washtenaw County in 1822.
The first township organization was Detroit, in Wayne County, in 1802.

Also organized in 1818 were two counties that survive in present-day Wisconsin.
Crawford was set up to govern the settlements on the upper Mississippi River from its seat at Prairie du Chien, Wisconsin, while Brown performed a similar function for the settlements around Green Bay.
These would become part of the Wisconsin Territory in 1836.

Oakland County, Michigan was created in 1819, and over time was subdivided into all or parts of Genesee, Lapeer, Sanilac, Shiawassee and Saginaw counties.
Saginaw County would be split further into eight separate counties, three of which (Isabella, Arenac and Midland) were established during the territorial period.

Lenawee County was created in 1822 from what had been Indian lands, and Hillsdale County was separated from it in 1829.
Other parts of Lenawee were turned into Cass and Berrien.
Branch also sprung fully formed from Michigan Territory in 1829.

Chippewa County was created from Michilimackinac County in 1826.

Kalamazoo County, established 1829 from St. Joseph County, was the dominant tract in Western Michigan and was divided and subdivided into many other counties: Allegan, Barry, Calhoun, Eaton, Ionia, Montcalm, Kent, Ottawa and Clinton (some created during the territorial period, others split off later).

Jackson and Ingham were created in 1829 from Washtenaw; Isabella was created from parts of Saginaw and Midland counties in 1831.
Gratiot County was also established in 1831, with land from Saginaw and Clinton counties.

Seven of the 12 counties created in 1829 were named for members of President Andrew Jackson's Cabinet, and one was named for Jackson himself.

Iowa County, with its seat at Mineral Point, was established in 1829 and transferred to the Wisconsin Territory in 1836.

Michigan Territory briefly governed lands west of the Mississippi, after the statehood of Missouri left the area north of the new state as unorganized territory; this comprised what is now Iowa and that part of Minnesota west of the river.
Such was the case until 1834, when that area was placed under the government of Michigan Territory.
Dubuque and Des Moines counties were created in 1834, and transferred to the Wisconsin Territory in 1836 upon its organization.

Milwaukee County was established in 1834 and was also transferred to Wisconsin Territory two years later.
Wayne County, Michigan, originally part of the vast Northwest Territory, was eventually whittled down into its current size by the separation of several tracts: Monroe in 1817, Michilimackinac County (later called Mackinac) and Macomb counties in 1818, St. Clair and St. Joseph counties in 1820 and Washtenaw County in 1822. The first township organization was Detroit, in Wayne County, in 1802.
Also organized in 1818 were two counties that survive in present-day Wisconsin. Crawford was set up to govern the settlements on the upper Mississippi River from its seat at Prairie du Chien, Wisconsin, while Brown performed a similar function for the settlements around Green Bay. These would become part of the Wisconsin Territory in 1836.
Oakland County, Michigan was created in 1819, and over time was subdivided into all or parts of Genesee, Lapeer, Sanilac, Shiawassee and Saginaw counties. Saginaw County would be split further into eight separate counties, three of which (Isabella, Arenac and Midland) were established during the territorial period.
Lenawee County was created in 1822 from what had been Indian lands, and Hillsdale County was separated from it in 1829. Other parts of Lenawee were turned into Cass and Berrien. Branch also sprung fully formed from Michigan Territory in 1829.
Chippewa County was created from Michilimackinac County in 1826.
Kalamazoo County, established 1829 from St. Joseph County, was the dominant tract in Western Michigan and was divided and subdivided into many other counties: Allegan, Barry, Calhoun, Eaton, Ionia, Montcalm, Kent, Ottawa and Clinton (some created during the territorial period, others split off later).
Jackson and Ingham were created in 1829 from Washtenaw; Isabella was created from parts of Saginaw and Midland counties in 1831. Gratiot County was also established in 1831, with land from Saginaw and Clinton counties.
Seven of the 12 counties created in 1829 were named for members of President Andrew Jackson's Cabinet, and one was named for Jackson himself.
Iowa County, with its seat at Mineral Point, was established in 1829 and transferred to the Wisconsin Territory in 1836.
Michigan Territory briefly governed lands west of the Mississippi, after the statehood of Missouri left the area north of the new state as unorganized territory; this comprised what is now Iowa and that part of Minnesota west of the river. Such was the case until 1834, when that area was placed under the government of Michigan Territory. Dubuque and Des Moines counties were created in 1834, and transferred to the Wisconsin Territory in 1836 upon its organization.
Milwaukee County was established in 1834 and was also transferred to Wisconsin Territory two years later.
Michigan Territory