Throughout U.S. history, various groups, because of some characteristic beyond their control, have been denied their civil rights and have fought for equal treatment under the law. All laws treat people differently on some basis, and the Supreme Court has come up with a formula to determine when that discrimination is constitutional. When a law treats people differently according to race or religion, the Court rules that it is making a suspect classification, which is subject to strict scrutiny to see if the state has a compelling purpose to pass the law. If not, it is struck down. Laws that discriminate according to gender are subject to an easier standard called an intermediate standard of review; and those that discriminate according to age or wealth are subject to the easiest standard for the state to meet, the minimum rationality test.

African Americans have experienced two kinds of segregation: that created by de jure discrimination, laws that treat people differently; and that created by de facto discrimination, which occurs when societal tradition and habit lead to social segregation. De jure discrimination, now illegal, included the passage of black codes prior to the Civil War and then, after Reconstruction, poll taxes, literacy tests, grandfather clauses, and other Jim Crow laws designed to return the South to the pre–Civil War days. By forming interest groups such as the National Association for the Advancement of Colored People (NAACP) and developing strategies of nonviolent resistance such as sit-ins and boycotts, African Americans eventually defeated de jure discrimination. De facto discrimination persists in America, signified by the education and wage gap between African Americans and whites. Programs like busing and affirmative action, which could remedy such discrimination, remain controversial. Although African Americans have made great strides in the past fifty years, racism is a persistent problem, and much inequality remains.

Native Americans, Hispanics, and Asian Americans have also fought to gain economic and social equality. Congressional control over their lands has led Native Americans to assert economic power through the development of casinos. Using boycotts and voter education drives, Hispanics have worked to stem the success of English-only movements and anti-immigration efforts. Despite their smaller numbers, Asian Americans also aim for equal political clout, but it is through a cultural emphasis on scholarly achievement that they have gained considerable economic power.

Women's rights movements represented challenges to power, to a traditional way of life, and to economic profit. Early activists found success through state politics because they were restricted from using the courts and Congress, and they were finally able to earn women the right to vote in 1920. After repeated efforts to pass the Equal Rights Amendment (ERA) failed, current efforts focus on the courts to give women greater protection of the law.

Gays, youth, the elderly, and the disabled enjoy the most fundamental civil rights, but they still face de jure and de facto discrimination. While moral concerns motivate laws against gays, social order and cost-efficiency concerns mark the restrictions against youth, the elderly, and disabled Americans.