One of the ideas ranking among the top ten in American history, is the creation of public schools and the public education system.
The creation of this system allowed for free access to education. It was no longer a privilege left solely to the richer members of the American population; it was and remains a right. All people, regardless of ability, can participate in this system. Students can now move from elementary school, to middle school, and finally to high school free of charge. Along with this, students are subsidized by the state at the college level, if they attend a state university.
The increased access to education, and higher education, promotes equality of opportunity. That is, people of all income brackets now have the same opportunity to nurture their talent, and achieve their potential. This is good for the individual but also for the US as whole. More educated citizens are more productive in the economy and better equipped to participate in a democracy.
It is disappointing that this should be seen as such a revolutionary idea.