Valley Forge was the winter encampment of the Continental Army, under the command of George Washington, during the American Revolutionary War. The Valley Forge encampment lasted six months, from December 19, 1777 to June 19, 1778. It was the third and harshest of the eight winter encampments that Washington and the Continental Army endured during the war.

The Philadelphia campaign (1777–1778) was a British military campaign during the American Revolutionary War designed to gain control of Philadelphia, the Revolutionary-era capital where the Second Continental Congress convened and formed the Continental Army and appointed George Washington as its commander in 1775, and authored and unanimously adopted the Declaration of Independence the following year, on July 4, 1776, which formalized and escalated the war.