How a con artist "reformer" shaped America's modern public schools.

Two centuries ago, London school reformer Joseph Lancaster swept into New York City to revolutionize its public schools. Pennsylvania and Massachusetts passed laws mandating Lancaster's methods, and cities such as Albany, Savannah, Detroit, and Baltimore soon followed. In Mr. Lancaster's System, Adam Laats tells the story of how this abusive, scheming reformer fooled the world into believing his system could provide free high-quality education for poor children. The system never worked as promised, but thanks to real work done by students, teachers, and families, Lancaster's failed reforms eventually led to the creation of the modern public school system.

Lancaster's idea was simple: instead of hiring expensive adult teachers, Lancasterian schools made children teach one another to read, write, and behave properly. America's city leaders poured the equivalent of millions of dollars into the scheme, built specialized school buildings featuring Lancaster's teaching machines, and offered him a huge salary. In London, where Lancaster opened his first school, the enthusiasm of city leaders was quickly and similarly followed by scandal and dismay. Lancaster borrowed money—even from the king of England—and spent it on fancy carriage rides and cases of champagne. Even worse, Lancaster proved to be a sexual predator. Kicked out of London, Lancaster brought his simplistic plan to the United States. His school model didn't work any better in US cities than it had in London, and Lancaster himself never changed his abusive ways.

Mr. Lancaster's System details how American cities created their first public schools out of the wreckage of Lancasterian failure. In the end, the most important people in this story are not self-proclaimed geniuses like Lancaster or elites like New York's mayor De Witt Clinton, but rather the thousands of parents and children who forced urban public schools to assume their modern shape.