In 1806, the Free School Society opened a school in New York City where one teacher, using student monitors, was in charge of a school of 1,000 students. That was the Lancasterian, or monitorial system, developed in England.
By the 1860s, the now-public system had smaller classes, but one city teacher still had 269 pupils, and another had 162. The superintendent said classes of 60 or more were acceptable but they should not exceed 100. By the turn of the century, the number was down to only 60, with students often sitting three to a seat. In all these variations, students learned.
Students in other nations generally outperform American youngsters, despite sitting in larger classes. Children of the refugee boat people from Vietnam had been in classes averaging 75 students in Southeast Asia yet performed far above average in the U.S.
The legal maximum for Japanese elementary school classes is 45, and the average class has about 33. In Japanese high schools, classes typically have 50 students. A Chinese immigrant said her classes in China had 50 to 60 students and worse teachers than here, yet she learned because expectations were higher. In South Korea, average class size is 43.