The court case should have been late 70s, early 80s --- as it was explained to me, it was ruled as unfair that some children got a college education, while others who graduated from the same school had to pay for college

ChatGPT didn't find any cases, but offered this:

  There were debates about whether military children attending base schools were receiving benefits not available to children in the local civilian school systems. This issue could have come up in various ways, such as in cases where military dependents might have access to college-level classes or subsidized education while local students did not.