Despite a fire in 1871 that destroyed the Central Business District, the city grew exponentially, becoming the nation's rail center and the dominant Midwestern center for manufacturing, commerce, finance, higher education, religion, broadcasting, sports, jazz, and high culture. The city was a magnet for European immigrants—at first Germans, Irish and Scandinavians, then from the 1890s to 1914, Jews, Czechs, Poles and Italians. They were all absorbed in the city's powerful ward-based political machines.