Which document’s anniversary did the United States Semiquincentennial mark?

The United States Semiquincentennial marked the 250th anniversary of the Declaration of Independence.

The Second Continental Congress adopted the Declaration on July 4, 1776. The document announced that the thirteen American colonies regarded themselves as independent states rather than colonies subject to Great Britain.

Thomas Jefferson drafted the principal text, while Benjamin Franklin, John Adams, Roger Sherman, and Robert Livingston helped revise it as the Committee of Five. Congress debated and edited the document before adopting it.

The Declaration is not the same document as the Constitution, which was drafted in 1787 and ratified later. The Declaration explains the colonies’ case for independence; the Constitution established the framework of the federal government.