What happened to laws aimed at ending child labor before 1919?

The Court's ruling took the public by complete surprise. It did not, however, diminish its support for the objectives of the Keating Owen Act. The New York Times concluded that child labor, like the sale of alcoholic beverages, might better be left to the control of the local authorities; but others regarded the decision as a blow to justice and thus an aberration. Clearly, the Court remained unconvinced that child labor was in itself a social evil. Congress reacted angrily, acting, only months after the opinion had been issued, to amend the Revenue Bill of 1919 to include a prohibitive tax on the products of child labor, a provision later ruled invalid by the child labor tax case of 1922 (Bailey v. Drexel Furniture Company). During the First World War, the War Labor Policy Board, under the direction of Felix Frankfurter, inserted a clause in all federal contracts of the time making the provisions of the Keating Owen Act mandatory for anyone selling equipment and other war material to the government. Before long, advocates of child labor reform discovered yet another alternative by which to achieve the implementation of a national policy restricting child labor--the amendment of the Constitution itself. In 1924 a proposed amendment was submitted to the states for consideration, but was never ratified by the requisite number. Once again, conditions had begun to change. The introduction of new technologies and innovative manufacturing techniques encouraged the employment of better motivated and more highly educated workers. Hostility toward child labor continued to grow, but the passage of higher state mandatory educational requirements and vigorous enforcement of truancy laws made employing children increasingly burdensome and uncertain. The 1920 census reflected this situation by recording a decline in child labor, a decline that would continue into the 1930s with the passage of the Fair Labor Standards Act of 1938, which established minimum wage and hour standards nationwide, discouraging the employment of minors. By setting minimum wages, it decreased incentives to hire children.