Really? Schooling is neither "radical" nor "new."
The ancient Greeks, Romans, Egyptians, and Indians all had schools - predominately for boys, but schools nonetheless.
Monasteries set up schools in Europe, but the most common way of educating the younger sons of the upper classes was to send a boy to a monastery at the age of seven or so *to live.* Many of these boys never returned home, becoming either lay brothers, monks, or priests. Girls were sent to convents in a similar manner. The book "Galileo's Daughter" is a compilation of letters which passed between the 17th century scientist and his daughter, who was sent to a convent around age 10.
There was no lower-class or peasant alternative to a monastic education, and thus the lower classes were resolutely illiterate for centuries in Europe.
Further, parent/child separation was widespread for economic reasons all throughout European and early American history. Parents had their children apprenticed out around age 10, and the apprentice went to live with the master, essentially receiving room, board, and training. These apprenticeships lasted many years,a nd the apprentice didn't normally run back home to his family.
In the 18th and 19th centuries, areas of Europe where schooling was widespread, literacy rates were high and scientific/technical development flourished. In areas of Europe where schooling was infrequent, literacy was less and so was economic progress.
Early Americans had widespread forms of schooling. The largely Protestant settlers were either Anglican (in which case they were well-educated and had fine prep schools for their boys, and "French" educations for their girls - i.e. French, drawing, and music), or evangelical, in which case they believed that salvation came from reading the Scriptures, and that literacy was absolutely necessary.
These early Americans formed schools - some were private, some were publicly funded (even if there was no colony-wide mandate for schooling.) Schools required that you know how to read and write *before* you entered, so "dame's schools" sprang up, where older women would teach their neighbors' children for pay.
When children went to school in early America, they went for long days (although not so many days per year, like today.)
The Little House books (Laura Ingalls Wilder) give many engaging and highly accurate accounts of prairie schooling in the 19th century. One of the first things Western settlers did when they had the population density was to form a school board and a subscription school district (i.e. a public school paid for by the parents who used it.)
When Catholic immigrants came in large numbers, many of the imported orders of nuns set up schools (in the Midwest & West, often German nuns who set up German-language schools.) Catholic schooling exploded in the late 19th century after the Cardinal of Baltimore (name escapes me) mandated that Catholics send their children to parish schools on pain of excommunication. (Was he a "radical?")
I am pointing this out because the comment made was not about *public* vs. *private* schooling. I grant that private schooling was a dominant feature in both the US and Europe for centuries. But *schooling* itself (as opposed to home schooling or no schooling) has been established for thousands of years. It's nursery-through-high-school homeschooling (exclusively) that's rare and radical among the literate.
Make that "compulsory schooling." Invented in Prussia in the early 1800s and imported to America around 1850. It's not an accident that Hitler rose to power in the birthplace of kindergarten.
There was no lower-class or peasant alternative to a monastic education, and thus the lower classes were resolutely illiterate for centuries in Europe.
Learning to read, prior to the invention of the printing press in the late 15th century, didn't make a lot of sense, since there was no printed material to read. A hand-copied Bible cost the equivalent of 3 years salary (roughly $100k today), which is why Bibles were often chained to pulpits.
Thereafter, Christians were generally satisfied with teaching their children how to read and write, along with a little bit of mathematics. After that, they were expected to learn on their own, if they were interested.