The First Amendment to the U.S. Constitution guarantees the right to freedom of expression. This freedom encompasses the right to speak freely, exercise religion openly, and gather peacefully, all without fear of government interference or retaliation. However, these rights have limits, and must be restrained in instances where they conflict with the rights of others. For this reason, only certain types of speech are considered "protected" by the First Amendment. Perjury and obscenity, for example, are never protected, and can be limited by the government as it wishes. Similarly, the law does not allow people to use freedom of religion as an excuse to act recklessly or exploit others.

The Fourteenth Amendment to the U.S. Constitution says that no state can deny any person within its jurisdiction equal protection of the law. In addition, the Fifth Amendment states that no person can be deprived of life, liberty, or property without due process. In addition to these Constitutional guarantees, there are also several federal and state laws that prohibit discrimination in various settings. The most notable of these are:

The Civil Rights Act of 1964: Prohibits discrimination in areas of education, employment, access to public businesses, and federal services.

Voting Rights Act: Prohibits discriminatory voter restrictions and registration practices.

Equal Credit Opportunity Act: Prohibits discrimination in loan applications, mortgage processing, and other credit transactions.

Fair Housing Act: Prohibits discrimination in housing sales and rental decisions.

However, "discrimination" can be a vague term, and "equal protection" does not necessarily always mean "equal treatment". There are many circumstances where the government may have a legitimate reason to treat different classes of people differently, and civil rights law has evolved standards of "scrutiny" to account for this. Whenever the government enacts a law or policy that treats different classes of people differently, the judicial system determines its validity by using levels of scrutiny that change depending on the classification of person being singled out. For instance, laws that treat people differently based on their wealth, handicap, or age, are subject to "rational basis" review. This means that the government can treat these people differently so long as the policy is "rationally related to a legitimate government interest". In contrast, laws that treat people differently based on race or religion, or infringe on certain fundamental rights are much more suspect, and are therefore reviewed using a "strict scrutiny" standard. This means that the classification will only be constitutional if it "necessary to a compelling government interest". Adding to this, Courts have ruled that the standard is only satisfied when the law is absolutely necessary to accomplish a compelling (desirable or important is not enough) interest, is has been "narrowly tailored" to accomplish only that goal, and no less restrictive means exist.

The Fourteenth Amendment guarantees that no person may be deprived of life, liberty, or property without "due process of the law". By its wording, this guarantee would seem to be simple- in order to take life, liberty or property, the government must go through a legal "process". However, the Supreme Court has expanded on this "procedural" due process guarantee a great deal, by creating the separate notion of "substantive" due process.

The legal process required under the “Procedural” element of due process is fair notice and a hearing by an impartial judge. In order to challenge a government action under this guarantee, an individual must show that they were a) deprived of a liberty or property interest, and b) either no legal process was used, or the process used was unfair or against the public interest.

Substantive due process, unlike procedural, is based on the idea that individuals have certain implied personal rights, and that the government cannot infringe on these rights regardless of the "process" it uses. The primary example of substantive due process rights is the right to privacy. Most people do not realize that the U.S. Constitution does not literally guarantee anyone’s privacy. In fact, the word “privacy” does not actually appear anywhere in the text of the Constitution. It is a judge-made right that is said to be implied by the Constitution’s other guarantees.

The U.S. Constitution, along with various other federal, state, and judge-made laws, guarantee certain individual rights and freedoms. These "civil rights" include the right to be free from discrimination in public settings, and to freely practice religion, express opinions, and peaceably assemble. Much of civil rights law is based on the Constitutional concept of equal protection, which generally requires the government to treat all people equally regardless of race, sex, religion, national origin, age, etc.

However, there is a common misconception about civil rights, which is that they are truly "inalienable" or absolute, and cannot be taken away. However in reality, all rights must have limits if civilized society is to function, and the extent of an individual's civil rights will vary greatly depending on context. For example, although we generally have the right to freedom of speech, we cannot say whatever we want, whenever we want. Telling lies in court or disclosing government or corporate secrets can get you sued, thrown in jail, or both, depending on the situation. Civil rights law, therefore, is not so much about defining the rights we all enjoy, but rather about settling disputes in situations where the different rights and liberties conflict with each other.