1900: Although it took some time for the public school system to grow in America, by 1900, 31 states were requiring children from the age of 8-14 to attend public schools.
1918: The demand for public education continued to grow, and by 1918, all states in America required that children at least complete elementary school.
1920s: From the 1920s on, more academic subjects were introduced. Schools focused on Mathematics, English, and Social Studies mainly.
Statistics: The number of students increased from 200,000 in 1890 to 1,000,000 in 1910, and to almost 2,000,000 by 1920. The percentage of youths aged 14 to 17 that were enrolled also increased from 7% in 1890, to 32% in 1920.