The Fourth of July (July 4th), also known as Independence Day, is a federal holiday commemorating the adoption of the Declaration of Independence on July 4, 1776, by the Continental Congress declaring that the thirteen American colonies regarded themselves as a new nation, the United States of America, and no longer part of the British Empire. Independence Day is commonly associated with fireworks, parades, barbecues, carnivals, fairs, picnics, concerts, baseball games, family reunions, and political speeches and ceremonies, in addition to various other public and private events celebrating the history, government, and traditions of the United States.
The Fourth of July's significance applies to every Harry Turtledovetimeline with a point of divergence after 1776, and numerous works have characters commemorating the 4th of July. It is germane only on very rare occasions.
About a year after the eruption of the Yellowstone Supervolcano and the effects it had on the weather, it caused a new Year Without a Summer. On the Fourth of July in Guilford, Maine, it was a grey day with snow drifting down from the sky although temperatures had reached the sixties once or twice in June.