Urban industrial development combined with mass transportation and urban growth destroyed the old pedestrian city of the past. The physical expansion of the city attracted industry, capital, and people. By the early 1900s, the modern American city, with its urban mass and distinct constituencies, was clearly taking shape. Cities grow in three ways: through physical expansion, by natural increase, and through migration and immigration.
In the late nineteenth century, immigration from domestic and foreign sources was the most important cause of urban growth, with native whites, foreigners, and African Americans being the three major migrant groups of the period. American cities had big businesses with more infrastructure and profit. Overall, the United States was more advanced than European cities but the environment was horrible. There was constant movement to and from geographic areas and constant movement within urban areas. Migration, in fact, provided one of the two paths to improved opportunity, with occupational change being the second path. Ethnic communes or immigrant districts emerged in America’s urban areas as migrants and the “new” immigrants poured into the country. Within these areas there was continuous cultural interface between foreign immigrants and American society. In the 1900, thirty percent of the urban residents were foreign born. The ethnic neighborhoods fostered and kept their own culture and services within their neighborhood. Urban African-Americans became one third of the population in the south cities but less than two percent in the North cities. Because of discrimination, there were limited job opportunities.
Rapid urban growth created and increased urban problems such as inadequate housing, overcrowding, and intolerable living conditions. This situation led to reforms that strengthened the hand of local government in regulating the construction of housing, but American attitudes toward the profit motive and toward