If I am remembering correctly, getting the weekend off was primarily pushed for by progressive Christian organizations (They needed a dedicated day to go to church, along with a work-free day for the sabbath) of course, this happened prior to the heavy conservative swing that defined most religious politics of the latter half of the 20th century. Depending on your views of the church, it's either surprising that they were the dominant progressive force of the first half of the 20th century, or surprising that they stopped being the dominant progressive force.