The Boston Tea Party was not a party, but one of the most famous examples of protest in American history. The leaders of the "tea party" were known as the Sons of Liberty. The Sons of Liberty and many of the citizens of Boston were angry at the British government. They were angry because the British government had taken steps to hurt the American tea business. It had given a British company control over the American tea business. This put American merchants out of business.
So what did the Sons of Liberty do? They planned to show the British government how angry they were. On December 16, 1773, they dressed up as Indians and boarded three British ships in Boston Harbor that were delivering tea. They took all 342 chests of tea and heaved them into the harbor, destroying the entire load. The event was first known as "The Destruction of the Tea" and only became known as the Boston Tea Party in the 1800s.