Answer:
The Supreme Court decision in Brown v. Board of Education showed that segregation is not compatible with the principle of equality before the law, guaranteed in the U.S. Constitution.
Brown v. Board of Education paved the way for other civil rights lawsuits and measures because schools were not the only thing that was segregated at the time (in the South). In the South, almost every public facility and service was segregated, and these places and services were desegregated thanks to a combination of civil activism, judicial decisions, and congressional action.