Known now as a day of patriotism and enjoying time off from work, the Fourth of July began the journey to becoming a quintessential American holiday in 1776, when the Second Continental Congress adopted the Declaration of Independence.

The Fourth of July has been celebrated across the nation since 1776. But when — and how — did Americans across the country agree to commemorate the holiday with a fireworks celebration?

There’s one night of the year where celebrations across the United States light up the map like no other. It’s the Fourth of July — when fine particulates fill the air.