Claim: In the United States, Detroit is the 21st-most populous city.

Detroit -LRB- -LSB- dᵻˈtrɔɪt -RSB- -RRB- is the most populous city in the U.S. state of Michigan , the largest city on the United States -- Canada border , and the seat of Wayne County . The municipality of Detroit had a 2015 estimated population of 677,116 , making it the 21st-most populous city in the United States . The metropolitan area , known as Metro Detroit , is home to 4.3 million people , making it the second-largest in the Midwest .   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 and its neighboring Canadian city Windsor are connected through a tunnel and the Ambassador Bridge , the busiest international crossing in North America . Detroit is best-known as the center of the American automobile industry , and the `` Big Three '' auto manufacturers General Motors , Ford , and Chrysler are all headquartered in Metro Detroit .   Detroit was founded on July 24 , 1701 by the French explorer and adventurer Antoine de la Mothe Cadillac and a party of settlers . During the 19th century , it became an important industrial hub at the center of the Great Lakes region . With expansion of the auto industry in the early 20th century , the city and its suburbs experienced rapid growth , and by the 1940s , the city had become the fourth-largest in the country . However , due to industrial restructuring , the loss of jobs in the auto industry , and rapid suburbanization , Detroit lost considerable population from the late 20th century to the present . Since reaching a peak of 1.8 million at the 1950 census , Detroit 's population has declined by more than 60 per cent . In 2013 , Detroit became the largest U.S. city to file for bankruptcy , which it successfully exited in December 2014 , when the city government regained control of Detroit 's finances .   Detroit 's diverse culture has had both local and international influence , particularly in music , with the city giving rise to the genres of Motown and techno , and playing an important role in the development of jazz , hip-hop , rock , and punk music . The erstwhile rapid growth of Detroit left a globally unique stock of architectural monuments and historic places of the first half of the 20th century , and since the 2000s conservation efforts managed to save many architectural pieces and allowed several large-scale revitalisations , including the restoration of several historic theatres and entertainment venues , highrise renovations , new sports stadiums , and a riverfront revitalization project . More recently , the population of Downtown Detroit , Midtown Detroit , and various other neighborhoods has increased . In 2015 , Detroit was named a `` City of Design '' by UNESCO , the first U.S. city to receive that designation .