Industrial expansion and population growth radically changed the face of the nation's cities. Noise, traffic jams, slums, air pollution, and sanitation and health problems became commonplace. Mass transit, in the form of trolleys, cable cars, and subways, was built, and skyscrapers began to dominate city skylines. New communities, known as suburbs, began to be built just beyond the city. Commuters, those who lived in the suburbs and traveled in and out of the city for work, began to increase in number. Many of those who resided in the city lived in rental apartments or tenement housing. Neighborhoods, especially for immigrant populations, were often the center of community life. In the enclave neighborhoods, many immigrant groups attempted to hold onto and practice precious customs and traditions. Even today, many neighborhoods or sections of some of the great cities in the United States reflect those ethnic heritages.
The industrial revolution also had a major impact on immigration. The ideal of success in business and prosperity fueled the rise in immigration. Immigrants came in search of riches but they were soon to find out that wealth was not what they received. The industrial revolution brought huge numbers of new immigrants from every