Why did the US enact compulsory education? The wikipedia article actually isn't very helpful, at least where the intentions of the people who campaigned for this are concerned. I seem to remember hearing in high school that this had something to do with the Progressives, and they were concerned that everyone (regardless of their ability to pay) needed a basic education. Am I remembering any of that right? I have also heard this was a way to limit child labor. My real interest is in the motivations: why did people at the time think that children should be educated, and how did their reasons change as the 19th century transitioned into the 20th? I'm down to read primary sources.
From about the mid-19th century on, there were four distinct trends occurring that all motivated, in unison, the development of compulsory education. These trends occurred throughout all of Western Europe as well as North America at roughly the same time.
First was the desire to eliminate child labour. By ensuring the registration of all children, and then assigning them all to designated schools and classrooms, legislation against child labour became much more effective. In many rural areas (including most of North America) the school year was deliberately scheduled around the planting and harvest seasons.
Second, growing nationalism created a desire to ensure assimilation of minorities. To that end, national curricula were designed so that a "national dialect" was taught to all children throughout each nation. Parisien throughout France and Algeria; Berliner Deutsch throughout Prussia and then Germany; Wiener Deutsch throughout Austria; British English throughout England; etc.
Third, increasing suffrage of first men and then women created a desire that citizens be capable of educating themselves about their world, and its political policies and platforms. In an age when the newspaper was king, this required the ability to read at a high school level.
Finally, the increasing technical demands of industrial jobs required a better educated workforce. A workforce capable of reading, writing, and basic arithmetic calculations, whether measuring parts, cashiering, or taking dictation, was fast becoming a requirement in an industrial society. Evidence for this is clear in the massive explosion of mail order sales in the latter half of the 19th century, leading into the development of the Sears Catalogue business in the 1890's. Prior to that time catalogue sales were pretty much restricted to books, but in the late 19th century much of a farm family's purchases were by catalogue, requiring that even the traditionally least literate segment of society become capable readers.
So, regardless of the governmental level at which the details of education policy were crafted and implemented, national policies in all of the four areas above drove the increasing trend towards universal education of minors. Details vary by nation, but in every Western Culture from Berlin to San Francisco, Oslo to Naples, national policies in these areas were driving educational policy towards universality.