The foundational pillars of American education had already begun to crack by the mid-1800s, but they did not come crashing down until the rise of the Progressives at the turn of the 20th century, arguably led by the charismatic and revolutionary John Dewey.
Against a backdrop of rising immigration, advancing technological and scientific knowledge, challenges to classical liberal thinking, and the transition from an agrarian society to an industrial society, the Progressives called for a variety of reforms that would fundamentally alter the course of the United States. The realm of education was one of the first that would drastically change. The burden of responsibility in raising one's children was beginning to be passed from parents to schools; and in the eyes of the Progressives, public schooling was not adequately bringing up America's youth for a modern, democratic future.
Horace Mann and other 19th century reformers had already taken American education a turn away from founding traditions, but Dewey believed that more needed to be done. To him, schools were failing to prepare children for societal life in a democracy (not a republic). Schools must do away with a regimented class schedule based on the "3 R's" in favor of a "work-study-play" method of learning. Dewey believed that education is a social process, that education is "a process of living, and not preparation for future living," and that through education society can shape its purposes, economy, and the direction it wants to move.
While Dewey talked about the importance of the individual, much of his work had to do with molding the individual to fit into a democratic society. Most Americans reading this piece have been shaped by his ideas and how they played out in the real world: group projects, standardized testing, schooling broken out by age (grade) rather than capability, yearbooks, child-centered learning, field trips, school newspapers, D.A.R.E., student government, gym/P.E., tech classes, etc.
The worldviews of many Americans have been shaped by Dewey and ideas rooted in progressive education. While certainly some of the ideas were good, the greatest indictment against many of Dewey's ideas, and progressive education overall, is the utter failure of the public education system by the end of the 20th century. Before finding a better way forward for education in America, one must pull back the curtain and discover the motives and goals of John Dewey and the Progressives.