The establishment of the American Civil Liberties Union (ACLU) involved several key figures, particularly Roger Baldwin, who helped found the organization in 1920. The ACLU aimed to defend and preserve individual rights and liberties as granted by the Constitution and laws of the United States. Baldwin and his colleagues championed civil rights, free speech, and privacy protections during a time of social upheaval. This organization has played a vital role in numerous landmark legal cases, making significant contributions to civil liberties in America, and continues to advocate for justice and equality today.