[3] As one of the "cabinet counties" it was named for the U.S. Secretary of the Navy John Branch under President Andrew Jackson.

The original founders of Coldwater were settlers from the northern coastal colonies – "Yankees", descended from the English Puritans who came from the Old World in the 1600s and who brought their culture.

During the early 1800s, there was a wave of New England farmers who headed west into what was then the untamed Northwest Territory.

Many traveled through New York State via the Erie Canal; the threat of Native Americans had been reduced by the end of the Black Hawk War.

These early settlers laid out farms, constructed roads, erected government buildings, and established post routes.

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

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

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