Further information: History of Miami, Florida Coral Gables was one of the first planned communities, and prefigured the development of the gated community and the homeowners association. It is famous for its strict zoning regulations. The city was developed by George Edgar Merrick during the Florida land boom of the 1920s. The city's architecture is almost entirely Mediterranean Revival Style. By 1926, the city covered 10,000 acres (40 km2), had netted $150 million in sales with over $100 million spent on development. Merrick designed the downtown commercial district to be only four blocks wide and more than two miles (3 km) long. The main artery bisected the business district. Merrick could boast that every business in Coral Gables was less than a two-block walk. The city used to have an old electric trolley system which was replaced by the popularity of modern automobiles, but now a new free circulator trolley system, initiated in November, 2003, runs down Ponce de León Boulevard. In 1925, roughly simultaneous to the founding of Coral Gables, the city was selected as the home to the University of Miami, which was constructed that year on 240 acres (0.97 km2) of land just west of U.S. Route 1, approximately two miles south of downtown Coral Gables. During World War II many Navy pilots and mechanics were trained and housed in Coral Gables.