The american revolution was a fascinating era that the AC themes had a lot to talk about. People just know very little about the actual history of the american revolution. And they outsourced the history to bulgarians (whiskey tango foxtrot!) instead of getting one of the hundreds of grad students who would have leapt at the chance to give the era justice.
Let me just toss a couple things out there for you. During the time period of the American revolution, there was basically ethnic cleansing between the colonists and the indians, we all know this. But what isn't really discussed is the various reactions people took. Some said that we need to engage in ugly massacres to scare the other guys off and ensure peace through terrors. Others took a more restrained approach. And there was even a group of hippie german lutherans who created proto refuge camps for displaced indians to try and stem the violence through calming things down. That last group there, sound familiar? Well it should because it's pretty much exactly what the assasins order talked about for AC1 and AC2. Of course when we get to that actual era... they forgot all that stuff.
Or consider the historical figure,
Kosciuszko. A globe traveling democratic zealot, he fought for liberty not only in the american revolution but also trying to defend his native poland against the partitions (by the triple alliance of prussia, austria and russia). He was pivotal to the battle of Saratoga, arguably the most important battle of the war. He worked closely with Benedict Arnold. This dude screams out from the rooftops that he is full of secret history possibility. In fact he probably was involved in a lot of lost conspiracies if you look at the stuff he did over his life. How is he depicted in AC3? Oh yeah, he isn't even depicted.
The problem isn't with the American Revolution era. It's a time period that perfectly encapsulates the nature of the Assasins organization as depicted in the first two game. The problem is that they didn't bother to actually do any freakin' history before making historical fiction. It was alright when they were talking with poorly documented events like the crusades and italian city states period. But when you get to the point where we have larger than life figures who are well documented, it starts to ruin thigns.