American Civil Liberties Union

The American Civil Liberties Union (ACLU) is a group of two non-profit organizations that fight for what they believe are important civil liberties issues. It was started in 1920 by Crystal Eastman, Roger Nash Baldwin, and Walter Nelles.
Some issues that are important to the ACLU are the First Amendment to the United States Constitution (which says that people have free speech and freedom of religion, as well as other rights), privacy, the right of people to be treated fairly if they are accused of a crime and arrested, and the right for everybody to be treated the same under the law. 
One way the ACLU tries to reach its goals is by helping people in court whom it believes are not being treated fairly by the law. The ACLU has lawyers that file lawsuits for people it represents. The ACLU also tries to change laws by teaching people about issues and by lobbying the government about what it believes.
Controversy.
Some people in the United States disagree with the ACLU. Some conservatives do not like that the ACLU believes that people have the right to an abortion and that it believes in the separation of church and state. Also, some of the people or groups that the ACLU has represented in court have been unpopular, such as the Westboro Baptist Church, which is famous for protesting the funerals of American soldiers who died at war.