Which document is the central historical milestone commemorated by the United States Semiquincentennial?

The Declaration of Independence is the central historical milestone commemorated by the United States Semiquincentennial.

The America250 celebration marks 250 years since the Second Continental Congress adopted the Declaration on July 4, 1776. The document announced that the thirteen colonies considered themselves free and independent states rather than territories governed by Great Britain.

The anniversary is not primarily a celebration of the Constitution, which was drafted in 1787 and ratified in 1788. Nor does it mark the Treaty of Paris, which formally ended the Revolutionary War in 1783. Those events are essential to American history, but they occurred after the Declaration.

The Declaration’s opening principles and list of grievances helped explain the political break with Britain. Its adoption date also established the July 4 holiday that Americans continue to observe as Independence Day.