From Quora: My answer to "Can a poor student with good grades go to Harvard for free?"

Yes. The best colleges in the US are generally “need blind” to the point that a student from a poor enough family could get a “free ride” at Harvard. I recall some kid who grew up on a goat farm somewhere in the Rocky Mountains who applied to Harvard because even state schools were simply too expensive (goat farming in the middle of nowhere probably doesn’t bring in much cash). A poor student would certainly be expected to work a work-study job (anyone on financial aid is expected to) and most likely have to take out some kind of student loans (hopefully just federally subsidized loans- I think private student loans should be illegal), but it depends on a number of factors (for example, how badly Harvard wants the student).