The heyday of educational wall charts lies roughly between 1870 and the mid 20th Century. During that period of time, hundreds of series were printed in huge numbers, covering an extensive range of subject matter for all educational levels. Most of the charts were produced in Germany. In the nineteenth century, after a thorough reorganization of the educational system, there was an enormous increase in the number of German schoolchildren and university students. Circulating loose prints or books in the crowded classrooms was not particularly easy. Large wall charts ā sometimes accompanied by textbooks ā provided the perfect solution. In the course of the nineteenth century, Germany developed into a superpower which dominated Europe intellectually, economically and politically. The educational wall charts printed by German publishing houses were sold all over Europe and in America.