Stock Photo - Detroit is the most populous city in the U. S. state of Michigan, the fourth-largest city in the Midwest and the largest city on the United Statesâ. “Canada border. It is the seat of Wayne County, the most populous county in the state. Detroit´s metropolitan area, known as Metro Detroit, is home to 4. 3 million people, making it the fourteenth-most populous metropolitan area in the United States and the second-largest in the Midwestern United States (behind Chicago). The Detroit metropolitan region holds roughly one-half of Michigan´s population. Detroit is a major port on the Detroit River, a strait that connects the Great Lakes system to the Saint Lawrence Seaway. The Detroit Metropolitan Airport is among the most important hubs in the United States. The City of Detroit anchors the second-largest economic region in the Midwest, behind Chicago, and the thirteenth-largest in the United States. Detroit was founded on July 24, 1701 by the French explorer and adventurer Antoine de la Mothe Cadillac and a party of settlers. With expansion of the automobile industry, the Detroit area emerged as a significant metropolitan region within the United States in the early 20th century, when the city became the fourth-largest in the country for a period. In the 1950s and 1960s, expansion continued with construction of a regional freeway system.