Kind of overlooked some MAJOR historical topics
I don't mean this as some sort of anti-American thing, all countries have their unflattering chapters. But seriously, re: Schoolhouse Rock, to purport to teach about major themes and events in American history, without ONCE mentioning slavery, well...
And of course, electing not to teach about slavery then neccessitates totally omitting any discussion of the Civil War, which was arguably THE definitive event in American history, and a pretty major catalyst in transforming the USA into the country that it it today, not just in regards to race either(also in regards to governmental and judicial powers, for example). It's kind of hard not to notice this abscence when you watch the series today on YouTube and whatnot.
I'm sure if it were made today, they would cover slavery and other race-related issues. And I remain a fan of the series, to be sure.