Cities grew very quickly after the Civil War ended. This was due in large part to the country’s industrialization. New jobs were created and they brought an influx of people from rural areas and more immigrants. In a forty-year time period three U.S. cities grew to over one million people. New York was the largest of the three, second only to London. The increased population also caused the cities themselves to grow in order to make room for more people. The skyscraper began to replace shorter buildings, thanks to the invention of the electric elevator. The cities also grew outward, creating the suburbs and mass transit systems for commuters. The growth also created segregated communities that were based on things such as race and income. The
