I have read a number of articles and book reviews that hammer the foundations of American education that were implemented in the early decades of the 20th Century -- particularly the pernicious influence of John Dewey on our education system. The whole point of "education" under that system was not to educate children, but to train them to be functioning parts in the machinery of the American "corporate state." Even something as simple as the bell that rang in the school yard in the morning and after recess had a very specific purpose: to prepare children for the day when they'd work in a factory or mine and respond to the same kind of bell or whistle at different times of the day.
The fact that Dewey's philosophy on education was built on the eradication of any religious aspect to a child's education was a clear indication of his motivations.
You’d be better off looking back at those days AS THEY REALLY WERE. Bells were rung because there were NO electrical systems to ring a modern bell system. There were NO electrically powered loudspeakers to tell the kids “time for school” or “recess is over”. I began school in an old building in 1939 that required a hand rung bell. We moved in 1944 and the ‘newer school’ had an automatic bell ringing system. Then in an even newer Junior High building there was a loudspeaker intercom system.
Those bells were telling the time to people who in the main had NO watches. And that education system “trained” the people who built the United States of America.