Teaching methods in the last 100 years or so have gone through drastic changes that are quite profound when contemplated upon. Where there was once the School master who dominated the scene by being the strict disciplinarian, now teachers are expected to keep discipline in class by keeping the students busy and all in a friendly manner too.
Where 100 years ago, the most important tools of learning were considered to be the primer as well as the bible, now, the internet, videos and lastly textbooks are taken as the most significant teaching tools.
But then, there is also the numbers to be considered. Where in 1850, there were only about 3. 68 million students getting a formal education in America, a century and a half later, in 2020 it has been projected that the number of students would rise to around 81 million.