The American Revolution didn't just happen once. In fact, it is still happening.
In 1689, England's Glorious Revolution shifted authority from crown to constitution. British Parliament essentially hired monarchs (William & Mary) and told them that they could have subjects but would - like everyone else - be themselves subject to the constitution.
About a hundred years later the Americans decided that if they had a constitution they wouldn't even need a monarch. It's worth remembering that George Washington was the first president in the history of the world. But of course it never occurred to the founding fathers, who thought that all men were created equal, that anyone other than white, property-owning, Protestant males should be able to vote.
The Revolution of 1776 was a beautiful thing but it didn't really change the the rights of most Americans. It took 34 more years before people (well, property-owning white males) of any religion could vote. It took 74 years before even white males who didn't own property could vote. 144 years before women could vote and 148 years before Native Americans were considered real Americans and also able to vote. 189 years later, minorities' voting rights were ensured. And it took nearly 200 years before the 18 year olds considered old enough to die for their country were considered old enough to vote for their leaders. (And it is probably no coincidence that since then we've not had a draft.)
The real limit to change is always the collective imagination. For all of their vision, it is not the least obvious that our founding fathers could conceive of an 18 year old black female casting the vote that might elect the next president.
Social progress is often a bet on the person who has yet to prove himself. By definition it almost has to be. Before 1920, women could not prove that their vote mattered for the simple reason that it did not.
A couple of centuries later, democracy is still spreading. Right here within our borders. Now that's a revolution.