How did the Declaration explain natural rights?

The Declaration of Independence explained natural rights by asserting in its famous second paragraph that all people are created equal, that they are endowed by their Creator with certain unalienable rights including life, liberty, and the pursuit of happiness, and that government exists to secure those rights. The full sentence reads "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."

Each phrase carried specific meaning. Self-evident meant that the truths required no proof beyond reflection on human nature; reasonable people could not disagree once they considered the question carefully. Created equal did not mean equality of talent, wealth, or condition but equality in fundamental rights and dignity, the quality that made every person a moral agent rather than property. Endowed by their Creator located the source of rights in nature or in God rather than in government, meaning that no king or parliament could legitimately take them away. Unalienable meant the rights could not be transferred, surrendered, or sold even by the person who possessed them; a slave could not validly sell his liberty.

Among these signaled that the list of life, liberty, and the pursuit of happiness was illustrative rather than exhaustive, leaving room for additional rights such as conscience, property, and self-defense. The next sentence completes the theory: governments are instituted among men to secure these rights, deriving their just powers from the consent of the governed, and when government becomes destructive of these ends the people have a right to alter or abolish it.

Thomas Jefferson drew the framework from John Locke's Second Treatise of Civil Government published in 1689, from George Mason's Virginia Declaration of Rights drafted on June 12, 1776 just weeks before, and from a broader Enlightenment tradition. The change from Locke's "life, liberty, and property" to Jefferson's "life, liberty, and the pursuit of happiness" expanded the scope of natural rights beyond mere ownership to include human flourishing in the classical sense.

The Declaration's natural rights theory had three radical consequences in 1776. It claimed universal application even though most signers held enslaved people, embedding a contradiction the country has wrestled with ever since. It justified revolution as a legitimate exercise of right when government failed in its duty. And it shifted the source of legitimate authority from divine right of kings to consent of the governed, a foundation later codified in the Constitution's preamble beginning "We the People."