...”My mother was teaching in New Jersey for many years after that time and said by 1975 she could see the quality of the children deteriorating with the rise of junk food and junk cereal”...
You know, by 1975 the Woodstock revolution had taken place which changed colleges into a place of anarchy over a span of only three years in the 1960s. Baby boomer parents did not stand up against the moral and educational decline because they wanted to give their little facists darlings everything they never had. The little Baby Boomers darlings turned out to the the most greedy, immoral, Godless, entitled group who ever lived in America.
Throw in heavy medal music, birth control, teacher’s unions and lawyers who were ready to sue teachers and schools over any kind of discipline and there you have it. The Boomers spawned the children and probably, the grandchildren your mother taught..It has only gotten worse since then.
I should add that my mother was teaching 3rd grade in a suburban bedroom suburb of New York. Mostly middle class students.