The main cause for the Revolutionary war was propaganda, almost every act and tax that was passed by the crown was blown out of proportion by the press. During this time there had been no laws that required the press to print the truth. The general public believed what they had read in the papers. Since only a few could read, most of every thing was through here say. Through the years propaganda had cause the anger towards the British to grow stronger and stronger until war seemed to be the only option.
In 1765 the stamp act was passed, this act stated that all official documents must be printed on a paper with an official seal on it. Obviously this stamped paper would have a hefty tax on it, but it was not retro active. The newspaper printed that it was retro active, so that every official document in the past was no longer legally binding. Such as marriage licenses, so all children that have came from previous marriages are bastards and your wife is a whore for getting pregnant in the first place.
In 1770 the Headlines read " BOSTON MASACRE ". The press stated that the British troops shot down unarmed citizens by the hundreds, that there was blood and body part everywhere of men, women, and children. When in fact, it was a small bar fight not much different than many in the past. For those that couldn't read Paul Revere engraved a plaque with a drawing on it with the British shooting the citizens.
All of this propaganda has cause so much anger that the first continental congress is created from a small group of secret rebels. This small group of rebels tries to recruit an army with little success. Rumors of this army made it back to the British army. By the time the story reaches the British it has been extremely exaggerated they hear things like the continently army has enough supplies for a 1000 men for 100 days. In April 1775 the British army marches towards Lexigington where they meet up with a small militia group.