Detroit is a place.
Detroit . The municipality of Detroit had a 2015 estimated population of 677,116 , making it the 21st-most populous city in the United States . Detroit is a major port on the Detroit River , a strait that connects the Great Lakes system to the Saint Lawrence Seaway . 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 . During the 19th century , it became an important industrial hub at the center of the Great Lakes region . In 2015 , Detroit was named a `` City of Design '' by UNESCO , the first U.S. city to receive that designation .