How did the growth of cities create problems for the working poor?

The working poor are working people whose incomes fall below a given poverty line. Depending on how one defines "working" and "poverty," someone may or may not be counted as part of the working poor.

The rapid growth of cities in the United States in the late 1800s created many social problems, especially for the urban poor. Progressive reformers such as Jane Addams worked to solve these problems