This boundary would include Chicago, Illinois, and a sizable strip of Wisconsin along Lake Michigan.

[8] These boundaries would be adjusted as Indiana and Illinois became states and as other counties were formed within Michigan Territory.

Due to the southwestern course of the river, this small portion of Canada actually lies to the south of Wayne County.

The highest elevation (990 feet (300 m)) in the county is near Northville, in Maybury State Park.

[10] Its first commissioners were Edward N. Hines, Cassius R. Benton, and automobile manufacturer Henry Ford.

While the commission was authorized by an 80% positive vote of county voters in a 1906 referendum, it was controversial and there was a Michigan state supreme court case pressed which found it unconstitutional.

Hines is credited with the idea of putting a painted line down a roadway's center to divide traffic, and other innovations that were later widely adopted.

[12] The commission claims credit for constructing the country's first mile of concrete-paved rural highway, a section of Woodward Avenue just outside the Detroit city limits.

[11] A number of the county road commissions' works are listed on the National Register of Historic Places.

Most Michigan county governments are structured according to state law, without a locally adopted charter.

[29] The county government operates the jail, maintains rural roads, keeps files of deeds and mortgages, maintains vital records for all areas except Detroit, administers public health regulations, and participates with the state in the provision of welfare and other social services.

Most other local government functions – police and fire, building and zoning, tax assessment, street maintenance, etc.

[11][13] The Wayne County Jail Division operates The Andrew C. Baird Detention Facility in Downtown Detroit, The Old Wayne County Jail in Downtown Detroit, and The William Dickerson Detention Facility in Hamtramck.

[30] Wayne County has backed the Democratic candidate for president in every election from 1932 onward, at times by large margins.

The last Republican candidate to carry Wayne County in a statewide election was Candice Miller when she won re-election to the Secretary of State office in 1998.