Washington began the Revolutionary War by being soundly defeated in New York, and swiftly retreating through New Jersey until both armies were forced into Winter Quarters.  faced with a dwindling army, expiring terms of volunteer service, no supplies to speak of and low morale he rolled the dice on a surprise attack into Trenton.  After the incredible success at Trenton on Christmas, Washington did the unexpected and moved inland TOWARDS , or rather between advancing British forces to hit the major supply depot at Princeton, inflicting a second bloody nose on the brits and cowing Cornwallis into taking the defensive despite his greatly superior numbers.  thus buying breathing space for the  the nascent Continental government to create a means of finance and supply, giving the lift of morale required to hold together the tiny hodgepodge army, and getting enough captured supply to keep their souls together through the toughest part of winter.  It was incredibly bold, courageous, and most importantly, lucky.