He replaced traditional readers, spellers and grammar books with children's own writing, literature, and teacher prepared materials. In 1883 Parker left Massachusetts to become Principal of the Cook County Normal School in Chicago, a school that also served to train teachers in Parker's methods. In 1894 Parker's Talks on Pedagogics, which drew heavily on the thinking of Fröbel, Pestalozzi and Herbart, became one of the first American writings on education to gain international fame.