I advise people to get this book and read it. I don't know if it's available free online, if it is and someone has a link, please post.
I assume Blumenfeld is a jew, from his name and background in New York, but it's not relevant to this work. Blumenfeld, along with Iserbyt and Gatto, is one of the top three public-schooling opponents/historians.
In this book, despite the title, there's a great history of public schooling in the US, which really shows you the origins of 'liberalism' here, in the battle between Calvinists and Unitarians, with the latter winning and becoming essentially pre-marxists or pre-liberals bent on forcing everybody to think the way they want through the medium of coerced universal public schooling, an idea the WASP elite got from Prussia, of all places.
Same ground is covered by Gatto, but this book does an excellent job of laying out the origins of a certain mentality, at least in America.