The Idea of Teenagers and Adolescents

The idea of teenagers and adolescents, we call it, did not exist in America before 1900. So what happened? Where did it come from? Well, I've just been watching some YouTube videos, reading some books, doing some research about this. It was created and who created it, do you think?Well, it was certain families, the super rich, the Rockefeller family, they started in oil and then went into banking,. The Carnegie family, Andrew Carnegie, banking, railroads, the Vanderbilts are still running the country.