On Christmas night in 1776, one of the longest nights of that year, George Washington and his tired troop crossed the Delaware on borrowed boats. This attack became successful because the Hessians were caught off-guard. It was not actually the exact winter solstice but just a few days later when the night was very long; Washington took advantage of the darkness and the drunkenness of the German armies guarding Trenton, N.J., for the British.