The correct answer to this open question is the following.
Unfortunately, you did not attach the text to use as a reference. However, doing some research we can comment on the following.
There is a text called "Education in America." If this is the case for your question, the correct answer is the following.
The text suggests that the cause behind the continued expansion of education in the early twentieth century is the efforts of the Progressive Movement that demanded reforms to the education system. This allowed the growth of educational institutions and the number of children that attended school in the United States. Due to this reformation, education changed from simply literacy and general knowledge to an education that focused on training students to be the new managers and directors of industries, factories, and companies. High School graduation rates increased tp 50% in the 1940s.
