St. Louis, the second largest city in Missouri, is the center of the metropolitan statistical area comprised of Franklin, Jefferson, Lincoln, St. Charles, St. Louis, and Warren counties in Missouri and Bond, Calhoun, Clinton, Jersey, Macoupin, Madison, Monroe, St. Clair, and Washington counties in Illinois. Since its founding St. Louis has undergone several significant stages of development, which parallel the nation's westward expansion, symbolized by the city's famous Gateway Arch. St. Louis enjoys a rich and culturally diverse life and a revitalized downtown commercial district. As one of the first regions in the country to confront defense cutbacks in the 1990s and develop plans for dealing with them, the St. Louis area has emerged as a national laboratory for the post-Cold-War economy.