Why do we celebrate the Fourth of July? What to know NBC Bay Area [Video]

The Fourth of July is Americana at its core: parades and cookouts and cold beer and, of course, fireworks.

Those pyrotechnics also make it an especially dangerous holiday, typically resulting in more than 10,000 trips to the emergency room. Yet fireworks remain at the center of Independence Day, a holiday 247 years in the making.

Here are five things to know about July Fourth, including the origin of the holiday, why we celebrate it and how fireworks became part of the tradition.

The holiday celebrates the Second Continental Congress’ unanimous adoption of the Declaration of Independence on July 4, 1776, a document announcing the colonies’ separation from Great Britain.

One year later, according to the Library of Congress, a spontaneous celebration in Philadelphia marked the anniversary of American independence.

But across the burgeoning nation, observations didn’t become commonplace until after the War of 1812. It quickly took off: The Library of Congress notes that major historic events in the 19th century, …