Volume 13 of the Revolutionary War Series documents a crucial portion of the winter encampment at Valley Forge, Pennsylvania, when the fate of Washington's army hung in the balance. The volume begins with Washington's soldiers hard at work erecting log huts to the general's specifications and building a bridge over the Schuylkill River under the direction of Major General John Sullivan. Most of the fighting that characterized the bloody year of 1777 had drawn to a close by Christmas, and although British foraging and raiding parties ventured out of Philadelphia from time to time, Washington's priority was no longer to fight General William Howe but to preserve his own army and prepare it for the next campaign.

The American army was badly in need of reform. Attrition and ineffective recruitment had left most of the Continental regiments dangerously weak, and the rising pace of officer resignations made apparent the need for an equitable pay and pensionary establishment. At the same time the battle losses of the previous summer and autumn had exposed severe problems in military organization, drill, and discipline. Washington hoped that a congressional camp committee would rectify some of these problems, and after consulting his officers on army organization, he submitted to the committee one of the longest, most detailed, and most thoughtful letters he ever wrote. The arrival in camp of a Prussian volunteer who styled himself the Baron von Steuben, meanwhile, promised to bring about improvements in drill and discipline. Washington also had to look to his own authority, as a dispute with Major Generals Thomas Conway and Horatio Gates seemingly threatened to undermine his command of the Continental army.

The turning point of the Valley Forge encampment came in February 1778, when a provision shortage led to what Washington called a "fatal crisis" that threatened the continued existence of the army. Poor management of the commissary department and a breakdown of transport, resulting from bad weather and an insufficiency of wagons, combined to bring about a logistical collapse that brought provision supplies almost to a halt. For many days bread was scarce and meat almost nonexistent. Soldiers, many dressed literally in rags because of the incompetence of the clothier general, threatened mutiny. Washington's efforts to save his army in this crisis mark one of the highest points of his military career and make up an important part of this volume.