Exploitation of children in the labor force at the beginning of this century gave rise to a national campaign leading to congressional passage of the Keating-Owen Act in 1916. The act prohibited from interstate commerce goods produced in factories or mines that employed children who either were under fourteen years of age or who were under sixteen years of age and worked more than eight hours a day. Despite its popular support, the Act was declared unconstitutional by the Supreme Court in Hammer v. Dagenhart (1918). The Court's decision involved several major issues: interpretation of the Fifth and Fourteenth Amendments to the Constitution, freedom of contract, police power of the states, and the interstate commerce clause. Review of previous Court decisions suggests that the justices were on less than solid legal ground in reaching their decision. Examination of the historical context of the decision, however, suggests other factors that may have played a more important role than judicial precedents. The debate prompted by Hammer v. Dagenhart has much relevance to such current issues as young agricultural workers, sex discrimination in industry, and the powers of the federal government vis-a-vis states and individual citizens.