The story goes something like this: In the mid 18th century, the British Empire abused its power over its American colonies and saddled the colonists with heavy taxes. After the taxes on tea were again increased in 1773, the colonists had finally had enough so they disguised themselves as Indians and threw a whole shipment of tea into the Boston harbour, which ultimately led to the American Revolution.
Although this story sounds very reasonable, it is a serious distortion of history. The British-American colonists did not protest against taxes being too high. Their slogan was “No taxation without representation,” which is not about the rate of taxation at all. In fact, taxes on the colonists were very low and the British Empire spent far more money on maintaining its American colonies than it received from them in tax revenue. In particular, the government had gone into considerable debt to finance the French and Indian War, which originated as a border dispute between British and French colonists on American soil, and then became part of the global Seven Years’ War.
What the colonists did take issue with was taxes being levied on them by the British Parliament, even though the colonies weren’t represented in Parliament. The colonists by and large did acknowledge that it was reasonable for the British government to get the colonies to contribute more money, but objected to being taxed directly by Parliament. Instead, they wanted Parliament to request money from the various colonial governments, who would then tax the colonists (which was considered legitimate because the colonists were represented in their colonial assemblies). They argued that this system had worked well in the French and Indian War and that there was no reason to change it.
Parliament didn’t go along with this reasoning and wanted more direct control, so in the wake of the French and Indian War, they passed a number of measures to raise tax revenue from the American colonies, all of which the colonists resisted through protests, smuggling, boycotts, intimidation, and mob violence. As a reaction to these protests, Parliament reduced or eliminated many of the taxes, hoping that this reduced set of taxes would be easier to enforce. One of the taxes they kept in place was an import duty on tea.
However, this import duty did not raise very much revenue since smuggled Dutch tea was cheaper than legally imported tea, which was required by law first to be shipped to London before it could be sent to the American colonies. Organising a boycott against taxed tea isn’t very hard to do when all you have to do to take part in the boycott is to buy cheaper tea. To change that dynamic (and because the East India Company was sitting on a surplus of tea), Parliament passed the Tea Act of 1773, which allowed the East India Company to ship tea directly to America. This would have made their legally imported tea slightly cheaper than the smuggled Dutch tea, thus hopefully breaking up the boycott.
This was the catalyst for the Boston Tea Party: not an increase in the taxes on tea, but actually a law that made tea cheaper. This would undercut both smugglers and the boycott effort against taxed tea.
The idea that the Boston Tea Party was about taxes being too high fits in nicely with the overall effort of mythologising the American Revolution. We can all sympathise with daring heroes who stand up to an overbearing government imposing oppressively high taxes. But men who dress up as Indians to commit property desctruction on a grand scale to protest against tea becoming cheaper? Not so easy a sell to a modern audience.