The signing of the Declaration of Independence by delegates from the 13 colonies of the United States in 1776 is celebrated on the 4th of July with barbecues, parades, concerts, picnics, and fireworks.

Usually referred to as the "Fourth of July" in the U.S., it is the only national holiday that’s best known by its date.

In Philadelphia, where the Declaration of Independence was signed, the first annual commemoration of independence was held in 1777. The first state to adopt the Fourth of July as a holiday was Massachusetts. It was not until 1870 that Independence Day became a federal holiday.