The Colonists couldn't go past These mountains, so they felt like they didn't have rights to explore. Also they just fought a war, which they were promised land but got basically none. So the colonists sent the king letters telling him that they will protest against him if he doesn't do anything about it.
HEY, STOP THROWING ROCKS AT US.
WE'LL SHOOT YOU
This is the Boston Massacre, and it started a big point in the revolution, where people got a lot more fed up with the king. The citizens where protesting, and now they are being shot.
This is the battle of Lexington/Concord, and this is where the First battle of the revolutionary war was. And the revolutionary war started from the colonists getting fed up from the king.