The Declaration of Independence, issued by the Second Continental Congress on July 4, 1776, publicly proclaimed 13 of Great Britain's colonial provinces in North America to be independent, sovereign states, and formally styled their union “The United States of America.”
In justifying the act of separation, the Declaration enumerated numerous grievances the 13 colonies had against King George III of Great Britain while it appealed to natural law, corporate and individual liberty, and the right to revolution—concepts widely accepted in the eighteenth-century European world generally and the Anglophone world in particular. After the American Revolution, the Declaration became one of the most important American state papers, cited repeatedly by political leaders, activists, and commentators in the United States and in the wider world.
One of the earliest and most famous examples was the publication of the “Declaration of Sentiments” by the Seneca Falls Convention for women's rights in July 1848. Authored principally by Elizabeth Cady Stanton, the Declaration of Sentiments rephrased the Declaration of Independence to include both men and women and went on to list rights that the established American political and legal order had denied to women—most important, the right to vote, the right to own property without qualification, and the right to equal citizenship. This marked what most historians consider to be the starting point of the modern American women's movement.
One attendee at the Seneca Falls Convention, former slave and abolitionist Frederick Douglass, would argue in an 1852 Independence Day oration (“What to the Slave Is the Fourth of July?”) that the Declaration's promise would remain unfulfilled as long as slavery existed in America.
A century later, in one of the defining episodes of the civil rights movement, Martin Luther King Jr.'s “I Have a Dream” speech to the August 28, 1963, March on Washington for Jobs and Freedom quoted the Declaration to great effect. Historians regard that speech and march as a defining moment leading to the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
The Declaration of Independence has also had a life beyond the borders of the United States. Issuing a declaration of independence became an important act for colonial peoples seeking to win independence from an imperial power. In his international history of the Declaration, historian David Armitage identified over a hundred declarations of independence issued by national groups between 1776 and the early 1990s. Among the most famous of the postcolonial declarations of independence was Ho Chi Minh's “Proclamation of Independence of the Democratic Republic of Vietnam,” which was issued on September 2, 1945, in the wake of the collapse of the Japanese Empire and explicitly (and ironically, given later events) quoted the American Declaration of Independence. Following the collapse of the Soviet bloc between 1989 and 1991, many of the former republics of the Soviet Union issued their own declarations of independence. Thus, the influence and legacy of the Declaration of Independence continue into the twenty-first century.