Question - According to the website, even though the government had passes laws in favor of desegregation, why was “black activism” still necessary?

According to the website, even though the government had passes laws in favor of desegregation, why was “black activism” still necessary?

Answer: 

Even after the Supreme Court declared that public school segregation was unconstitutional, black activism was necessary to compel the federal government to implement the decision and extend its principles to all areas of public life rather than simply in schools.