What did the Declaration establish?

The Declaration of Independence established the philosophical basis for American government by stating that all people are created equal and possess unalienable rights, that government exists to secure those rights, that legitimate authority rests on the consent of the governed, and that when government becomes destructive of these ends the people have the right to alter or abolish it. These propositions shaped four foundations of American political thought.

The first foundation is natural rights. The Declaration treats life, liberty, and the pursuit of happiness as rights that exist before government and cannot be transferred or surrendered. Government does not create rights but exists to protect them. This framework, drawn from John Locke's Second Treatise of Civil Government from 1689, supplied the moral grammar for the Bill of Rights ratified December 15, 1791 and for every subsequent rights amendment, from the Thirteenth Amendment ending slavery in 1865 to the Nineteenth Amendment guaranteeing women's suffrage in 1920.

The second foundation is consent of the governed. Government's just powers derive from the people's consent, expressed through elections and through written constitutions. The Constitution opens with "We the People" precisely to embody this principle. The popular sovereignty doctrine made it possible to argue that the people, acting through ratifying conventions in 1787 to 1790, could establish a new constitutional order superior to the existing state governments.

The third foundation is the right of revolution. When government fails to secure rights, the people may alter or abolish it. The doctrine justified the Revolution itself, and it provided rhetorical resources for later movements. Frederick Douglass invoked it on July 5, 1852 in his speech "What to the Slave Is the Fourth of July?" Abraham Lincoln invoked it on November 19, 1863 in the Gettysburg Address. Martin Luther King Jr. invoked it on August 28, 1963 in the I Have a Dream speech. Each used the Declaration's principles to demand fulfillment of its promise.

The fourth foundation is equality. The opening declaration that all men are created equal established a baseline that the country has spent two and a half centuries trying to reach. The Fourteenth Amendment ratified July 9, 1868 added a constitutional guarantee of equal protection. The Civil Rights Act of 1964 and the Voting Rights Act of 1965 enforced it through federal law. Same-sex marriage was recognized by the Supreme Court in Obergefell v. Hodges (2015) on similar logic.

Although the Declaration is not law, the Supreme Court, presidents, and political movements have treated it as the moral charter of the United States, the standard against which laws and policies are measured. Its principles inform the Constitution but operate in a separate register: the Constitution structures government, while the Declaration tells government what it is for.