I don't know but I can explain the logic of it.
Look at voting patterns broke down by marital status. Single women vote feminism/big government, married women traditional values and small government. When you have a war situation that permanently eliminates the possibility of a man to provide for them, they turn to the government to step in.
But there had to be an underlying root cause here somewhere, especially on the male side. Previous wars, in European and other cultures, led to monogamous societies relaxing restrictions so women could marry. For some reason, this time in England and the US the ruling class rejected that in favor of forcing spinsterhood and opening up feminism.
Why, I'm not sure. Might have something to do with the rise of the industrial ruling class; one which finds families and stay at home moms less profitable. I don't know if that is the case but it is distinctly possible because it would not have been the last time they openly undertook society wide social engineering to the detriment of millions of people.
The rise of feminism led to the breakdown of the family, which led to out of wedlock births, and the children of single mothers are way more likely to end up committing crime and being unable to form healthy relationships.