The Fourth of July is about all things American: parades, cookouts, cold beer and of course, fireworks. Those pyrotechnics remain at the center of Independence Day, a holiday 247 years in the making.

The impact fireworks can have on air quality can be quite striking and seemingly outsized given their relatively small explosive force. And there have been stark examples in recen

It's been 249 years since the Declaration of Independence was passed by the Continental Congress in 1776, which the holiday commemorates.

Independence Day parades, another Joey Chestnut win and fireworks marked Friday's Fourth of July celebrations across the U.S. The big picture: Millions of Americans traveled for the holiday, facing sweltering heat,