Answer :
Skyscrapers began to dominate city skylines as mass transit, such as trolleys, cable cars, and subways, was built. New communities, known as suburbs, began to spring up just outside of the city. Commuters, or people who live in the suburbs and commute into and out of the city for work, began to grow in number.
Cities in the United States grew at a rapid pace between 1880 and 1900. Cities in the United States grew by about 15 million people in the two decades preceding 1900, owing primarily to industrial expansion.
Many of those who contributed to city population growth were immigrants from all over the world. During this time, a steady stream of people from rural America migrated to the cities. Between 1880 and 1890, nearly 40% of townships in the United States lost population due to migration.
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