<P> A salute of one gun for each state in the United States, called a "salute to the union," is fired on Independence Day at noon by any capable military base . </P> <P> In 2009, New York City had the largest fireworks display in the country, with more than 22 tons of pyrotechnics exploded . It generally holds displays in the East River . Other major displays are in Chicago on Lake Michigan; in San Diego over Mission Bay; in Boston on the Charles River; in St. Louis on the Mississippi River; in San Francisco over the San Francisco Bay; and on the National Mall in Washington, D.C. </P> <P> During the annual Windsor - Detroit International Freedom Festival, Detroit, Michigan hosts one of the world's largest fireworks displays, over the Detroit River, to celebrate Independence Day in conjunction with Windsor, Ontario's celebration of Canada Day . </P> <P> The first week of July is typically one of the busiest United States travel periods of the year, as many people use what is often a three - day holiday weekend for extended vacation trips . </P>

Who did the us win their independence from