The Montessori school programs are good, unorthodox, but really good. This is more than likely why the price to attend is so high ($$$).
I do not have any research at my fingertips; however, my nephew was enrolled in a Montessori school. The kids learned a lot about history by visiting museums. Since my nephew showed interest in art, the school encouraged him to learn more about the time period of the artist, Michaelangelo for example, which would lead to learning more about other events of the period. I hope this helps. Thank you.
In Montessori classes, children should be taken to visit different places having historical importance. There should be simulation of the the historical incidents in the classroom too.