1900s: By the beginning of the decade, more than two million children in the United States work in factories. Reformers persuade state legislatures to pass laws regulating child labor. Some states prohibit the employment of young children. Other states limit the employment of older children to eight to ten hours a day or bar them from working at night or in dangerous conditions. Still other states require that children obtain literacy before they are sent to work.

1920s: In the 1920s, children and adolescents generally enjoy more leisure time and less responsibility for family support. No major laws regarding child labor are passed, although reformers continue to be interested in the issue.

Today: All states require that children attend school, generally from age six to sixteen, and laws prevent children under the age of fourteen from working, with the exception of specific jobs. Many...