In the twentieth century, urban areas were defined as communities of more than 2,500
Explanation:
During the Civil War, American cities expanded even faster as industrialisation and globalisation began. By the turn of the 20th century, the US eastern coast towns were almost inconceivable, and many of their inhabitants were still living in misery. Often extremely corrupt is their local government, police forces, and companies.
Apart from this increase of urbanisation, the US has become more and more global since its foundation. More than 3/5 of the US population today resides in an urban area (usually defined as an integrated region with a minimum population of 2,500) and much less than a quarter is living in a rural area.
No it affected Germany and other countries due to lack of trading and money
More Americans were now able to move to the suburbs.
Population growth after World War II was a cause of expansion of cities into suburbs. The prices of homes in suburbs were more affordable to middle class families, due to lower land prices and new building practices like tract housing. With the growth of the suburbs, improvement of roadways became a priority. The Federal-Aid Highway Act passed in 1956 advanced and enabled further growth of the suburbs surrounding city centers.
B:
Economic problems and the lack of jobs