The United States achieved independence in the year 1776. This landmark event was officially declared on July 4, when the Second Continental Congress adopted the Declaration of Independence, primarily authored by Thomas Jefferson. The declaration announced the colonies' separation from British rule, outlining the colonies' grievances against King George III and asserting their rights to self-governance. The struggle for independence was marked by the American Revolutionary War, which lasted from 1775 to 1783. The principles of freedom, democracy, and individual rights expressed in the Declaration have since become foundational values of the United States and influential worldwide.