Obviously, the U.S. Constitution doesn’t guarantee education for everyone, but do all the state constitutions?
I guess the better question would be, which state constitutions/laws don’t guarantee education, if any?
Perhaps not quite the answer to your question but–
I remember participating in a thread about property taxes being used for schools/education many months ago. From what I read, the original colonies valued education so much that they specifically mandated moneys to be collected from people who owned land to be used to educate the populace. This was inportant right from the getgo. Perhaps not a right but important enough to be mandated in laws.
Strangely, I hadn’t given it much thought. Education was nowhere near universal in the ninteenth century. Reformers like Horace Mann and Labor Unions lobbied for about a hundred years to establish the idea of educationa as a right.
As for as the actual legal basis for that right, although some states may include such a right in their constitutuions, I don’t think it is actually necessary. All states offer public education. Because they offer it, it must be equally accessible to all. This is supported both by the 14th amendment and by Federal Law. Title 1, 7, 9 etc.
Well, about 30 seconds on Google yielded this from the New York Constitution:
You’re on your own for the other 49 states.
Damn - that’s as fine a definition of ‘socialised’ as I’ve heard in quite a while…whatever next 
Don’t anyone start telling George W about this crazy left wing stuff.
I think you will find that the concept of public elemenary school education goes back to the earliest days of the colonies/states. Extending this concept to high schools (and even colleges), however, is a fairly modern (late nineteenth/ early twentieth century) development.