Why did the U.S. Supreme Court reverse its previous rulings in the 1908 Muller v. Oregon case to uphold an Oregon law that limited women to a ten-hour workday?
Long hours endangered women and therefore the entire human race. CorrectCorrect. The answer is b. The Supreme Court was swayed by the logic of a mass of sociological evidence gathered by Florence Kelley and Josephine Goldmark that demonstrated the ill effects of long hours on the health and safety of women and therefore on their reproductive capacities. The ruling set a precedent, but one that rested on women's fundamental difference from men and their need for special treatment because of their childbearing capacity. (See section "Grassroots Progressivism" in your textbook.)

Hans Curt Muller was the owner of the Grand Laundry who tried to force Emma Gotcher, a unionist connected to the Shirtwaist and Laundryworkers’ Union, to work past the ten hours allotted by the state law. When a local judge fined Muller, he appealed the ruling, which got to the U.S. Supreme Court.

Muller v. Oregon confirmed an Oregon law restricting the workday for female workers to ten hours. The court accepted the idea that it was important for society to protect the bodies of potential mothers, as the defense´s had manifested in the Brandeis Brief.