Damn, was hoping the next one would be the Russian Revolution
But, American Revolution should be very cool as well. Seeing as it has to take place in a major urban centre (without major gameplay tweaks) I'd say it'll likely take place in Philidephia, seeing as you'd be able to interact with Washington, Adams, and maybe have Franklin be the new DiVinci!
Other then that, will guess that the main character is likely going to be part native American. Reason is Philadelphia was founded by William Penn, who fled to America to escape persecution of the Quakers, and wanted to make a place where everyone could worship freely. As well, he created a very good relationship with the local natives as he bought the land from them, despite it being 'granted'.
I'd guess, if the main character is on the American side (likely), he'd have Oneida heritage, as they were one of the two tribes that sided with the Americans, as well, assisted Washington in Valley Forge.