Before industrialization, in 1790, only 5% of the U.S. population lived in cities, and no city had more than 50,000 residents. Up until the 1830s, urban population growth was minimal. However, beginning in the 1830s, as industry expanded rapidly, urban populations began to grow more quickly. Between 1840 and 1850, the urban population nearly doubled, and it doubled again from 1850 to 1860. Many rural villages saw sharp population declines as strong, healthy farm youth moved to cities in large numbers.

By 1910, rural populations still accounted for more than half of the total, and 36% of the workforce was employed in agriculture. By 1920, urban residents made up 51% of the population, surpassing the rural population. This demonstrates that in the United States, urbanization and industrialization progressed in a coordinated fashion over roughly 100 years, eventually achieving an urban majority.

Immigrants from Europe and other countries played a key role in American industrialization. After the Civil War, the U.S. government enacted the Immigration Incentive Act. Between 1820 and 1928, about 38 million immigrants arrived in the United States. This influx, along with natural population growth, fueled rapid population expansion—from 3.93 million in 1790 to 105.7 million in 1920—greatly accelerating both industrial and agricultural development.