During the Battle of Princeton, a cannon ball went through a window of Nassau Hall of the College of New Jersey (now known as Princeton University) and hit a portrait of King George II (George III's grandfather and predecessor), lopping off his head. A mark made by another cannon ball that hit Nassau Hall during the battle can still be seen to this day.
The friction between General Washington and General Gates portrayed in the film was very real. In fact, Gates was allegedly involved in a conspiracy known as The Conway Cabal, a plot to oust George Washington as Commander-in-Chief in 1778 and replace him with himself. Gates' name surfaced again in the Newburgh Conspiracy, another plot to oust Washington in 1783.
Though he cast his lot with the Patriot cause, Major General William Alexander claimed to be the Earl of Stirling, a Lord in the Peerage of Scotland. The claim, however, was never fully substantiated. Officers (including Washington) and men alike often referred to him as Lord Stirling.
The Battle of Trenton was over in less than an hour. American losses were 2 killed and 5 wounded. One of the wounded was Lieutenant James Monroe, the future Fifth President of the United States. Lieutenant Monroe was also reputed to be the man standing next to George Washington and holding the American flag in Emanuel Leutze's famous painting, "Washington Crossing the Delaware". Also, it was widely believed that the Hessians were intoxicated as a result of their Christmas celebrations. That has been proved by historians to not be the case.
General Horatio Gates was originally an officer in the British army, but emigrated to America before the American Revolution. In 1745, he was mustered into service as number 15 on his regimental roster. Mustered in as number 16 was the man who would surrender his sword to Gates at Saratoga less than a year later: General Sir John Burgoyne.