Detroit is the largest city in the U.S. state of Michigan and the seat of Wayne County. Detroit is a major port city on the Detroit River, in the Midwest region of the United States. Located north of Windsor, Ontario, Detroit is the only major U.S. city that looks south to Canada. It was founded in 1701 by the Frenchman Antoine de la Mothe Cadillac.It is known as the world's traditional automotive center — "Detroit" is a metonym for the American automobile industry — and an important source of popular music, legacies celebrated by the city's two familiar nicknames, Motor City and Motown. Detroit and the surrounding region constitute a major manufacturing center, most notably as home to the Big Three automobile companies, General Motors, Ford, and Chrysler. The city is an important center for global trade with large international law firms having their offices in both Detroit and Windsor. About 80,500 people work in downtown Detroit, comprising 21% of the City's employment. There are hundreds of offices and plants in the automotive support business including parts, electronics, and design suppliers. The domestic auto industry is primarily headquartered in Metro Detroit. New vehicle production, sales, and jobs related to automobile use account for one of every ten jobs in the United States. The area is also an important source of engineering job opportunities.