According to natural rights theory, as described by philosophers such as John Locke, everyone is born with an equality of certain rights, regardless of their nationality. Since they come from nature or from God, natural rights cannot be justly taken away without consent. As the Declaration of Independence asserts, natural (or “inalienable”) rights include “life, liberty, and the pursuit of happiness.” Other natural rights are protected in the Bill of Rights, including freedom of speech, religion, and press.
The Founders believed that it is an important purpose of government to protect peoples’ natural rights. Thomas Jefferson wrote in the Virginia Statute for Religious Freedom that infringements of conscience were a violation of natural rights; James Madison included protections from government abridgement of natural rights in the Bill of Rights. Belief in natural rights theory led many Founders, notably James Otis, to denounce slavery as a violation of natural rights. The Ninth Amendment addresses those natural rights not specifically listed in the Constitution and the Bill of Rights, but which the people retain.
Later documents, including the Declaration of Sentiments and Resolutions, and Letter from Birmingham Jail, refer to natural rights as the basis for protesting unjust treatment of women and African Americans.