Several factors contributed:
* Office and Clerical Jobs: The growth of the office sector in the mid-20th century created a demand for skilled workers who could type, operate office machines, and perform administrative tasks. A high school education became increasingly important to qualify for these often better-paying and more respectable jobs than what was traditionally available to women.
* Teaching: Though teaching had always employed some women, the expansion of public education and increased demand for teachers provided more opportunities for women with high school diplomas and, increasingly, further education.
* Nurses and Allied Healthcare: The healthcare sector also saw expansion, offering more opportunities for women, though these often required additional training beyond high school. However, a high school diploma was a prerequisite for entry into nursing programs.
* Manufacturing (in some cases): While often physically demanding, some manufacturing jobs in the post-WWII era opened up to women, particularly those requiring a slightly higher skill level, making a high school education more beneficial.
It's important to note that these opportunities weren't equally accessible to all women, particularly women of color who faced significant systemic barriers to education and employment. The increased opportunity was tied to broader societal shifts, including the gradual erosion of gender roles and the growing emphasis on education as a pathway to economic advancement. It wasn't just the jobs themselves, but the societal shift towards valuing women's contributions outside the home that made completing high school more attractive and necessary.