If you draw your boundaries of the "founders" small enough maybe you can avoid the slaveowners, but that would be ignoring most of them. And, the wealth of America is based not on "freedom" or "liberty," but was mostly created on the backs of slaves, on broken treaties, and the exploitation of workers. Pretending that our founders were infallible heroes requires ignoring reality.

And I feel sorry for your kids then, that you'd rather keep them ignorant than have them learn about the reality of the world. Sex ed in schools is critically important, parents are historically terrible at teaching it, and think that if they just keep their kids ignorant that everything will be all right. Never works. The priority for teachers should be making sure that kids learn things, not keeping parents happy. If you want your kids kept in the dark, then homeschool them.