The major event commemorated on the Fourth of July in the United States is the Declaration of Independence, adopted on July 4, 1776. This pivotal document announced the thirteen American colonies' separation from British rule and articulated their right to self-govern through the assertion of inalienable rights, life, liberty, and the pursuit of happiness. The day is marked by celebrations across the U.S. including fireworks, parades, barbecues, and public events. It represents the birth of the nation and the principles of democracy and freedom, making it one of the most significant national holidays.