Prominently displayed in “Seven Men who Rule the World from the Grave”.
A great book that documents this point extensively is, JOHN DEWEY AND THE DECLINE OF AMERICAN EDUCATION: HOW THE PATRON SAINT OF SCHOOLS CORRUPTED TEACHING AND LEARNING by Henry T. Edmondson III.
One of the biggest pillars of learning that progessive educators have tried to destroy is rote memorization. Like in your math tables. Rote memorization was a staple of my grade school years. I don’t know if they still have teachers anywhere standing at the blackboard with a pointer in hand leading the class in reciting the tables like the nuns at my Catholic grade did. But if they’re not, they should be. Rote memorization creates the foundation from which kids can build on what they’ve learned. You shouldn’t try to hit homeruns until you can first be sure you can make contact with the ball.