A data point: it's been a while since my spring break corresponded to Easter. I'm not sure if my high school's did, but my mom's school gives them Good Friday off and nothing else. College put break in March; the semester ended at the end of April. I don't remember if we got Good Friday off. I think Iowa does the same-- break's in March, Easter's usually not.
My mother's high school in New York has a February break in addition to winter and spring. Energy crisis back in the seventies led to the best-placed break in the history of breaks.