The historical event celebrated on July 4th in the United States is Independence Day. This day commemorates the adoption of the Declaration of Independence, which occurred on July 4, 1776, marking the formal separation of the Thirteen Colonies from British rule. The Declaration, primarily authored by Thomas Jefferson, articulated the colonies' grievances against King George III and the desire for self-governance. Independence Day is celebrated nationwide with fireworks, parades, barbecues, and various patriotic displays. It serves as a reminder of the values of freedom and democracy that the United States was founded upon, fostering national pride and unity among Americans.