Here's an old example about one of the many ways in which occupations can become segregated by sex:
Disney Rejection Letter to a Woman, 1938 pic.twitter.com/PLwosc5vzo— History In Pictures (@HistoryInPix) March 30, 2018
I have written a piece about how economists have tried to explain why women would still, in 2018, crowd into lower-paying female-dominated jobs.