|Location State of Michigan|
Government County government
|Populations 2,156 (Keweenaw) – 1,820,584 (Wayne)|
Areas 508 square miles (1,320 km) (Cass) – 5,966 square miles (15,450 km) (Keweenaw)
Subdivisions cities, towns, townships, villages, unincorporated communities, census designated place
There are 83 counties in the U.S. state of Michigan. The boundaries of these counties have not changed substantially since 1897. However, throughout the 19th century, the state legislature frequently adjusted county boundaries. County creation was intended to fulfill the goal of establishing government over unorganized territory, but a more important goal was encouraging settlement by surveying the land and dividing it into salable sections.
The creation of counties generally occurred in two stages. First the boundaries of a county were declared and given a name. The county appeared on maps, even though this may have been the entire extent of a county's tangible existence for several years. During this period, the as-yet–unorganized county was attached to another already organized county for administrative purposes. The legislature frequently changed the administrative attachment of these unorganized counties. Residents of such an attached county could petition the legislature for organization, which was the granting of full legal recognition to the county.
There are many cities and villages that span county boundaries in Michigan, including its capital, Lansing. For a few years during the early 1970s, split cities briefly had authority to petition to change the county boundaries to accord with the city boundaries. The only city to take advantage of this brief opportunity was New Baltimore (previously split between Macomb County and St. Clair County; now completely in Macomb). This transfer of territory from St. Clair to Macomb was the only county boundary change in Michigan since the early 20th century.
The state constitution of 1850 permitted an incorporated city with a population of at least 20,000 to be organized into a separate county of its own. The Constitution of 1908 retained this provision, but raised the population threshold to 100,000. No city was ever organized into an independent county in this fashion and when a new Constitution took effect in 1963, the provision was removed.
Michigan's boundary with Illinois is formed by Lake Michigan, and three counties have water boundaries with Illinois: Berrien County, Van Buren County, and Allegan County. Michigan also has a boundary with Minnesota, which is formed by Lake Superior. The water boundary in this instance is formed by two counties: Ontonagon County and Keweenaw County.
Nine counties have names invented by the ethnologist Henry Schoolcraft, usually adapted from parts of Native American words, but sometimes having parts from Greek, Arabic and Latin roots. Schoolcraft's made-up words have disputed sources. While he was a devotee of Native American words and culture, some of his words may have originated with tribes from other areas of the country, such as New York or the Northeast, where many settlers to Michigan came from. Real Native words were eradicated, and he substituted made-up words, sometimes with a kernel of Indian language or sound in them.
A second group of four counties were renamed for Irish locales (counties Antrim, Clare, Roscommon and Wexford), apparently because it was close to the heart for certain Michigan legislators or their constituents.
Ten counties, the so-called "cabinet counties", were named for persons who served in Andrew Jackson's presidential administration, which was tied to Michigan's anticipated ascendancy to statehood. Eight were named in 1829. Livingston County was named in 1833. Cass County was also named in 1829, but Governor Lewis Cass did not become a member of Jackson's Cabinet until 1831.
- Brown County formed in 1818 from unorganized territory when Michigan Territory was expanded to include area west of Lake Michigan upon formation of the state of Illinois. Transferred to Wisconsin Territory in 1836 and continues as Brown County, Wisconsin.
- Keskkauko County formed in 1840 from part of Mackinac County. Renamed Charlevoix County in 1843. Annexed to Emmet County in 1853. Reformed as Charlevoix County from Emmet County in 1869.
- Crawford County formed in 1818 from unorganized territory when Michigan Territory was expanded to include area west of Lake Michigan upon formation of the state of Illinois. Transferred to Wisconsin Territory in 1836 and continues as Crawford County, Wisconsin.
- Des Moines County formed in 1834 from unorganized territory. Transferred to Wisconsin Territory in 1836 and continues as Des Moines County, Iowa.
- Dubuque County formed in 1834 from unorganized territory. Transferred to Wisconsin Territory in 1836 and continues as Dubuque County, Iowa.
- Iowa County formed in 1830 from part of Crawford County. Transferred to Wisconsin Territory in 1836 and continues as Iowa County, Wisconsin.
- Isle Royale County formed in 1875 from part of Keweenaw County. Returned to it in 1897.
- Manitou County formed in 1855 from parts of Emmet County and Leelenau County. County government was disorganized in 1861 and attached for administrative purposes to Mackinac County. In 1865, it was attached to Leelanau and reattached to Mackinac in 1869. County was abolished in 1895 and absorbed by Charlevoix County and Leelanau County.
- Milwaukee County formed in 1834 from part of Brown County. Transferred to Wisconsin Territory in 1836 and continues as Milwaukee County, Wisconsin.
- Omeena County formed in 1840 from part of Mackinac County. Annexed to Grand Traverse County in 1853.
- Wyandot County formed in 1840 from part of Mackinac County. Annexed to Cheboygan County in 1853.