"The Motor City" Detroit was once the wealthiest city in the United States.

Due to its advantageous geographical location, Detroit, known as the "Motor City," developed into the industrial center of the United States at an early stage. It was once the wealthiest city in the United States and the first city in the country to pave concrete roads and have a highway system. At its peak, the population reached 1.85 million, making it the fourth largest city in the United States. Detroit manufactured 80% of all cars in the United States and 25% of all cars in the world. The annual salary of automobile workers was as high as $140,000, exceeding the average salary of American university professors.