What is the X in X-mas?
A valley in eastern Pennsylvania that served as quarters for the American army in one winter (1777–1778) of the Revolutionary War. George Washington, who was commanding the army, had been forced to leave Philadelphia, and his troops suffered from the cold and from lack of supplies. Though many deserted, Washington managed to maintain the morale of the rest. He was aided by Baron von Steuben, a German officer on his staff, who trained the men in the soldiering practices of Europe.
in the American Revolution, Pennsylvania encampment grounds of the Continental Army under General George Washington from December 19, 1777, to June 19, 1778, a period that marked the triumph of morale and military discipline over severe hardship. Following the American failures at the nearby battles of Brandywine and Germantown, Washington led 11,000 regulars to take up winter quarters at Valley Forge on the west bank of the Schuylkill River, 22 miles (35 km) northwest of Philadelphia (which at the time was occupied by the British). The site was considered a defensible one, strategically located on leading trade routes and near farm supplies.