The current success and broad presence of Montessori is based on a rich history. For over 100 years, the Montessori method has been quietly revolutionizing education. There are more than 5,000 Montessori schools in the United States and more than 20,000 in 110 countries worldwide. Association Montessori Internationale has affiliate societies in 24 countries over four continents and 62 training centers worldwide.