The transition to this period is not sharply defined. I date the end of the change about 1920.
Industry requires more education than farming.
During the early homesteading days, to maybe the second or third grade. Just enough to sign their names, read simple English and figure change in stores. As the complexity of technology increased, educational requirements increased with it. By WW2, nothing less than High School would qualify people for jobs that paid living wages. Industrialization brought with it complusory schooling.