When data from the U.S. census of 1900 revealed the extent of working children in America, people concerned about their welfare began to agitate for social reform.
- In 1909, the Bureau of Labor Statistics issued a landmark, 19-volume study about women and children in the work force. It revealed that more children were employed in the South (especially in cotton mills) than in New England. In some cases, children's wages were needed to avoid family hardships, but such was not always true.
- By 1913, all but nine states required children to be at least 14 before they could work in factories.
- In 1916, Congress passed its first child labor law (the Keating-Owen Bill) which prevented certain goods made by children from being sold outside the state in which they were made. The U.S. Supreme Court found the law unconstitutional, however, because it overstepped the federal government's power to regulate interstate commerce.
- Undaunted, Congress tried again - and failed again - to regulate child labor. Reviewing the second law in 1918, the Supreme Court (in Hammer v Dagenhart) held: "The power of Congress to regulate interstate commerce does not extend to curbing the power of the states to regulate local trade."
- In 1924, Congress tried a different approach and proposed a Constitutional Amendment which would have allowed the federal government to regulate child labor. That amendment was not ratified by the states.