Fireworks are a mainstay of American holidays, but how much do you really know about them?
* The earliest documentation of fireworks dates back to seventh-century China. They were invented more than 2,000 years ago in China and used to scare off "mountain men."
* Originally the fireworks were a combination of saltpeter, sulfur and charcoal.
* These fireworks came only in orange and white, but creators figured out how to broaden their palette by adding different salts. The hardest color to make is blue.
* Americans have been setting off fireworks to celebrate Independence Day since 1777.
* Most large fireworks contain a rocket and a shell. This rocket can reach speeds of 150 miles per hour and fly as high as 200 meters.
* U.S. consumers purchase 163.6 million pounds of fireworks annually. Fireworks displays consume an additional 23.1 million pounds.
