The **American Civil Liberties Union (ACLU)** is a prominent nonprofit organization founded in 1920 to defend and preserve the individual rights and liberties guaranteed by the U.S. Constitution, particularly the Bill of Rights. It emerged from the National Civil Liberties Bureau, which was established during World War I to protect free speech and support conscientious objectors against government repression[1][2][3]. The ACLU’s mission centers on protecting **First Amendment rights** (free speech, religion, assembly), **equal protection under the law**, **due process**, and **privacy rights**. It actively pursues this through litigation, legislation, public education, and community outreach, often taking on cases that involve marginalized groups traditionally denied rights, including racial minorities, LGBTQ+ individuals, immigrants, and labor unions[2][4]. Historically, the ACLU has participated in numerous landmark civil liberties battles. Early on, it opposed the **Palmer Raids** targeting radical immigrants (1920), defended the right to teach evolution in the famous **Scopes Trial** (1925), and was virtually alone in opposing the **Japanese American internment** during World War II (1942)[6]. The organization also played a key role in the **Brown v. Board of Education** decision (1954), which ended racial segregation in public schools, and won major free speech victories like **Tinker v. Des Moines** (1969), protecting students’ rights to protest[6]. The ACLU has remained influential and sometimes controversial for its steadfast defense of civil liberties irrespective of political pressure. Today, it operates nationwide with affiliates in all 50 states, continuing to address modern issues such as government surveillance, racial profiling, LGBTQ+ rights, and education equality[3][4][6]. For business and technology audiences, the ACLU’s work intersects with digital privacy, government overreach, and free expression in the internet era, making it a key defender of constitutional freedoms amid evolving technological landscapes. Its