Ubisoft mentioned in its E3 presentation of Assassin’s Creed III that Connor’s story will span thirty years before, during, and after the Revolutionary War.
A span of thirty years may be part of a plan that Ubisoft will use to emulate an immersive story comparable to the story we had with Ezio Auditore. The upcoming plot already has a lot of content that touches on the beginnings of America’s foundation, so there may be much, much more that Ubisoft has in store for the "actual" events of the American Revolution.
Stay tuned to PSU as updates on the topic arise!