A day or so ago one Nikki Fisher submitted a letter to the JT editor asserting a "founding fathers' mandate of free education for all." And today, I challenged this assertion at root river siren, here, scroll to "In Defense of Teachers" thread. Read the lefty responses for fun. I especially enjoyed Sean's efforts, including his citing of section 16 of Jefferson's Land Ordinance of 1785 for "establishing a mechanism for funding public education."
You won't find anything remotely approaching a mandate for a free public education from our founders, as none exists. But the exercise will provide a window into the essence of leftiness, wherein you can twist, fabricate, exaggerate, etc... until you have convinced yourself that what you wish to be true is indeed true, actual truth be damned.