The area of the current city was originally inhabited by the Menomonee and Potawatomi Indian tribes. European explorers, trapper, and traders used the Milwaukee River through the middle of the current city as a means of transportation.
Later, somewhere between 1834 and 1836, Follett and Brink surveyed the land to create the town of Mequon. Around this time, settlers came from New York and England, soon followed by German and Irish immigrants. In 1839, a group of immigrants from Saxony settled near the Milwaukee river. In the same year, twenty families from Pomerania founded ‘Freistadt’ (German Free place) in western Mequon township. The first Luthern church in Wisconsin was built by these families in 1840.
John Henry Thien, an wealthy immigrant from Saxony, travelled north from Milwaukee and settled along the Milwaukee River, where his family made a dam and grist mill. This area, one square mile in the middle of Mequon township, later was incorporated as the village of Thiensville in 1910.
The town of Mequon was incorporated as the City of Mequon in 1957.