American intellectual life in the early 20th century has a dirty secret and its name is Eugenics. Alex Tabarrok points out an excellent article by Thomas C. Leonard on Protecting Family and Race: The Progressive Case for Regulating Women’s Work (PDF). Leonard makes the point that Progressive support for exclusionary labor legislation for women, including the minimum wage, was based among other things on ensuring “that women could better carry out their eugenic duties as ‘mothers of the race’”. Though most know that eugenics had some sort of open popularity prior to the Nazis giving it a bad name, few know how thoroughly it was supported by all the “best and brightest”. Here’s a partial list from Leonard’s paper: Margaret Sanger, founder of Planned Parenthood, Sidney Webb, George Bernard Shaw, T. S. Eliot, D. H. Lawrence and economist Irving Fisher.
Progressives, in part for eugenic reasons, wanted to make women and other groups unemployable. Their chosen tool: the minimum wage.
...these progressives argued that minimum-wage-induced disemployment was a social benefit. Legal minimum wages and other statutory means of inducing undesirable groups to leave the labor force were, in the progressive view, a eugenic benefit.