What progressive reform was most successful in reducing the prevalence of child labor in the united states in the early 1900s

The Keating-Owen Child Labor Act of 1916 is one of the premiere reforms that had to be dragged through congress. President Woodrow Wilson would begin its building blocks starting in 1908 with little urgency, as he felt that kind of government oversight to be unconstitutional. The Child Labor Act of 1916 would find itself passed, however two years later it would be overturned. However it would be the founding building blocks of the later 1938 'Fair Labor Standards Act'. Thus the Keating-Owen Child Labor Act of 1918 is most successful by setting a trend of public dismay for child labor in government branches, as well as inspiring better drafted legislation to combat child labor.