We've been reading The One Best System, by David Tyack, for class. Here's on interesting tidbit I came across (about nineteenth century schools):
"Schools, like other institutions, were supposed to counteract or compensate for indulgent or neglectful families." (p. 72)
I can't say with any authority to what extent this was true throughout the twentieth century, but the current movement toward "paternalistic" or "no excuses" schools seems to echo that same philosophy. Indeed, I presented that as one logical policy option given that we know that non-school factors influence achievement more than in-school factors.