Which document's adoption is commemorated by the United States Semiquincentennial?

The United States Semiquincentennial commemorates the adoption of the Declaration of Independence.

The Second Continental Congress adopted the document on July 4, 1776, announcing that the thirteen American colonies regarded themselves as independent states. Thomas Jefferson drafted the initial text, while John Adams, Benjamin Franklin, Roger Sherman, and Robert R. Livingston served with him on the Committee of Five that presented it to Congress.

The Declaration explained the colonies’ case against British rule and stated political principles about equality, rights, and government. Its best-known opening argument says that people possess inherent rights and that governments derive their powers from the consent of the governed.

The Declaration is sometimes confused with the Constitution because both are foundational American documents. The Declaration announced independence in 1776; the Constitution established the federal government’s framework in 1787. The 250th anniversary being celebrated in 2026 is tied specifically to the Declaration.