20th century

 
In 1904 Ford founded the Ford Motor Company. Ford's manufacturing—and those of automotive pioneers William C. Durant, the Dodge brothers, Packard, and Walter Chrysler—reinforced Detroit's status as the world's automotive capital; it also served to encourage truck manufacturers such as Rapid and Grabowsky.

With the introduction of Prohibition, smugglers used the river as a major conduit for Canadian spirits, organized in large part by the notorious Purple Gang. Strained racial relations were evident in the 1920s trial of Dr. Ossian Sweet, a black Detroit physician acquitted of murder. A man died when shots were fired from Ossian's house into a threatening mob who gathered to try to force him out of a predominantly white neighborhood.


Labor strife climaxed in the 1930s when the United Auto Workers became involved in bitter disputes with Detroit's auto manufacturers. The labor activism of those years brought notoriety to union leaders such as Jimmy Hoffa and Walter Reuther. The 1940s saw the construction of the world's first urban depressed freeway, the Davison and the industrial growth during World War II that led to Detroit's nickname as the Arsenal of Democracy.

Industry spurred growth during the first half of the twentieth century as the city drew tens of thousands of new residents, particularly workers from the Southern United States, to become the nation's fourth largest. At the same time, tens of thousands of European immigrants poured into the city. Social tensions rose with the rapid pace of growth. The color blind promotion policies of the auto plants resulted in racial tension that erupted into a full-scale riot in 1943.

Consolidation during the 1950s, especially in the automobile sector, increased competition for jobs. An extensive freeway system constructed in the 1950s and 1960s had facilitated commuting. The Twelfth Street riot in 1967, as well as court-ordered busing accelerated white flight from the city. Commensurate with the shift of population and jobs to its suburbs, the city's tax base eroded. In the years following, Detroit's population fell from a peak of roughly 1.8 million in 1950 to about half that number today.

The gasoline crises of 1973 and 1979 impacted the U.S. auto industry as small cars from foreign makers made inroads. Heroin and crack cocaine use afflicted the city with the influence of Butch Jones, Maserati Rick, and the Chambers Brothers. Renaissance has been a perennial buzzword among city leaders, reinforced by the construction of the Renaissance Center in the late 1970s. This complex of skyscrapers, designed as a city within a city, slowed but was unable to reverse the trend of businesses leaving Downtown Detroit until the 1990s.

In 1980, Detroit hosted the Republican National Convention which nominated Ronald Reagan to a successful bid for President of the United States. By then, nearly three decades of crime, drug addiction, and inadequate policies had caused areas like the Elmhurst block to decay. During the 1980s, abandoned structures were demolished to reduce havens for drug dealers with sizable tracts of land reverted to a form of urban prairie.

In the 1990s, the city began to receive a revival with much of it centered in Downtown Detroit. Comerica Tower at Detroit Center (1993) arose on the city skyline. In the ensuing years, three casinos opened in Detroit: MGM Grand Detroit, MotorCity Casino, and Greektown Casino which debuted as resorts in 2007-08. New downtown stadiums were constructed for the Detroit Tigers and Detroit Lions in 2000 and 2002, respectively; this put the Lions' home stadium in the city proper for the first time since 1974.The city also saw the historic Book Cadillac Hotel and the Fort Shelby Hotel reopen for the first time in over 20 years. The city hosted the 2005 MLB All-Star Game, 2006 Super Bowl XL, 2006 World Series, WrestleMania 23 in 2007 and the NCAA Final Four in April 2009 all of which prompted many improvements to the downtown area.

The city's riverfront is the focus of much development following the example of Windsor, Ontario which began its waterfront parkland conversion in the 1990s; in 2007, the first portions of the Detroit River Walk were laid, including miles of parks and fountains. This new urban development in Detroit is a mainstay in the city's plan to enhance its economy through tourism. Along the river, upscale million dollar condominiums are going up, such as Watermark Detroit, some of the most expensive the city has ever seen. Some city limit signs, particularly on the Dearborn border say "Welcome to Detroit, The Renaissance City Founded 1701.