Describe the shift of living by farmers in the 1800's. Why did they start to move?

Americans increasingly moved into cities over the course of the late nineteenth and early twentieth centuries, a movement motivated in large measure by industrialization.

Eleven million people migrated from rural to urban areas between 1870 and 1920, and a majority of the twenty-five million immigrants who came to the United States in these same years moved into the nation’s cities.

By 1920, more Americans lived in cities than in rural areas for the first time in US history.