The United States celebrates the Fourth of July, or Independence Day, with fireworks as a tradition continued down through history since the initial year the country's independence was celebrated. The first celebration, which came one year after the Declaration of Independence was signed, began and ended with 13 fireworks being set off from the city's commons.
After that first celebration in Philadelphia, Boston held its own celebration with fireworks, and the tradition grew from there. Explorer Richard Byrd even set off fireworks in Antarctica. The original tradition behind fireworks was to symbolize the 13 states of the union as 13 fireworks were set off at the beginning and of the celebration. However, it evolved as more states joined the union.