The philosopher Socrates once said, "I am that gadfly which God has given the state." While the American Civil Liberties Union (ACLU) might have a quarrel with the "God" part, the group has at times proved a stinging critic in its efforts to defend individual rights. It acts as a legal and legislative advocate in matters related to civil liberties and the Bill of Rights. The ACLU has participated in such cases as the 1925 Scopes trial (challenged a ban on teaching evolution), Brown v. Board of Education (school desegregation), Roe v. Wade (abortion rights), and Romer v. Evans (gay and lesbian rights). The group, which has more than 500,000 members, has offices throughout the US. It was founded in 1920.