Montessori began to develop her philosophy and methods in 1897, attending courses in pedagogy at the University of Rome and reading the educational theory of the previous two hundred years. In 1907, she opened her first classroom, the Casa dei Bambini, or Children’s House, in a tenement building in Rome. From the beginning, Montessori based her work on her observations of children and experimentation with the environment, materials, and lessons available to them. She frequently referred to her work as "scientific pedagogy".
Montessori education spread to the United States in 1911 and became widely known in education and popular publications. However, conflict between Montessori and the American educational establishment, and especially the publication in 1914 of a critical booklet, The Montessori System Examined, by influential education teacher William Heard Kilpatrick, limited the spread of her ideas, and they languished after 1914. Montessori education returned to the United States in 1960 and has since spread to thousands of schools there.
Montessori continued to extend her work during her lifetime, developing a comprehensive model of psychological development from birth to age 24, as well as educational approaches for children ages 0–3, 3–6, and 6–12. She wrote and lectured about ages 12 to 18 and beyond, but these programs were not developed during her lifetime.
Trademark status
The term "Montessori" is in the public domain, so anyone can use the term with or without reference to her work.