The diocese of Detroit was established by Pope Gregory XVI in 1833, more than 100 years after French settlers built their first church here. At the time, the diocese included all of Michigan, Wisconsin, Minnesota and portions of the Dakotas, east of the Mississippi River.
The diocese predates even the state of Michigan, which did not join the union until 1837. At that time, the boundaries of the diocese were changed to fit into Michigan’s newly-established borders.
Ste. Anne de Detroit Church was the first church built by settlers in 1701. The church served as the diocese's first cathedral from 1833 to 1848.
In 1937, Detroit was elevated to an archdiocese and His Eminence, Edward Mooney was named as our first archbishop. In the following decades the region’s population grew steadily, which required the expansion of many parishes under Mooney.
Today, the Archdiocese of Detroit comprises the six counties of southeast Michigan—Lapeer, Macomb, Monroe, Oakland, St. Clair and Wayne.