By using a team of Civil Rights lawyers, historians, social scientists, and even a psychologist, it fought to prove that equal education was not being provided to African American children. Thurgood Marshall, who later became a United States Supreme Court Justice, argued that segregation was being used to keep “the people who were formerly in slavery as near to that stage as possible”. The Supreme Court unanimously agreed, with Chief Justice Earl Warren reading the decision out-loud to a packed courtroom. Many states vehemently opposed this decision and continued to resist. Some states closed their public schools, others made school attendance optional, and in Little Rock, Arkansas the National Guard had to be activated to enforce the law. Hundreds of school districts were sued to compel the states to comply with the Brown v. Board of Education