The McCollum Memo is a set of instructions that were written by the U.S. Supreme Court in 1948. It tells school districts in the United States that it is against the law to treat students differently because of their race. This means that all students must be treated fairly, no matter what their race or ethnicity is. The memo was written after the Supreme Court decision in the case of McCollum v. Board of Education, which held that segregated schools were unconstitutional. All school districts in the United States must follow the McCollum Memo, or they can be punished.