In the United States, our National Day is July 4th, Independence Day. This observes the day in 1776 that the United States declared that they were breaking away from British colonial rule. Thus, in addition to the parties, fireworks, and parades, we also get to poke fun gently at the British, who of course are now our allies. (They of course can chide us for being uncouth and never developing our own language... :D)