The American Civil Liberties Union (ACLU) is a nonprofit organization founded in 1920 that focuses on defending and preserving individual rights and liberties guaranteed by the U.S. Constitution and laws. It works on a wide range of issues, including free speech, privacy rights, and equal protection under the law, often through litigation, advocacy, and public education. The ACLU operates through a network of state affiliates and engages in various legal battles to protect civil rights for all individuals, regardless of their background. It also provides resources and support for those facing civil liberties violations, aiming to promote justice and equality in society.