[1] The county's name is shortened from "Michilimackinac", which referred to the Straits of Mackinac area as well as the French settlement at the tip of the lower peninsula.

Michilimackinac County was created on October 26, 1818, by proclamation of territorial governor Lewis Cass.

On April 1, 1840, areas in the Lower Peninsula were laid off to create 30 new counites.

At this time, the County of Michilimackinac more closely resembled its modern configuration, including only a portion of the Upper Peninsula closest to the Straits of Mackinac, plus several islands.

In 1882 the county seat was moved from Mackinac Island to St. Ignace, Michigan, which had been founded as a French Jesuit mission village during the colonial years.

Religiously, Christianity is the predominant religion for the county and region of the Upper Peninsula.

Mackinac County is part of the Roman Catholic Diocese of Marquette.

Since the 1964 landslide of Lyndon B. Johnson, it has only supported a Democrat twice, and neither time with a majority of the vote.

The county government operates the jail, maintains rural roads, operates the major local courts, keeps files of deeds and mortgages, maintains vital records, administers public health regulations, and participates with the state in the provision of welfare and other social services.

The county board of commissioners controls the budget but has only limited authority to make laws or ordinances.

In Michigan, most local government functions — police and fire, building and zoning, tax assessment, street maintenance, etc.