Answer:
During the post-war years, racial segregation in northern schools existed mainly because of school districts laws requiring such separation of the races
Step-by-step explanation:
The major reason was that schools had laws that prevented them to coexist in the same areas. There were schools for afro-Americans and there were schools for Caucasians. There were also public places that afro-Americans couldn't visit because there was so much omission of the "Plessy v. Ferguson" that they started to discriminate afro-Americans. The Plessy v. Ferguson required similar spaces for both. However, it was never executed, until schools started to go against it.