Volume 19 of the Revolutionary War Series documents Washington's activities during the winter and early spring of 1779, when the bulk of his army was encamped at Middlebrook, New Jersey, strategically situated where the Watchung Mountains rise from the coastal plain in the middle of the state. Washington took advantage of the relative quiet of this period to consult with a congressional committee of conference in Philadelphia. He returned to Middlebrook in early February and devoted himself yet again to reorganizing and reinvigorating the Continental Army. Recruitment problems, disputes among officers over rank, and compensation woes had grown old, but Washington corresponded at length with state officials and Congress in order to keep an effective fighting force in the field.

Winter camp also allowed Washington to consider future military operations. Emphasis fell on planning a punitive expedition against Indians of the Six Nations and Loyalists whose raids had terrorized settlers along the Pennsylvania--New York frontier. Washington's most immediate challenge was simply understanding the geography of this largely unknown region, and he sought information from anybody who had direct experience with the terrain and the Indian inhabitants, a group that included army officers, prisoners, land surveyors, interpreters, traders, and missionaries. Washington carefully sifted through these reports, observations, and opinions. To aid analysis, he consolidated the most pertinent materials, in his own handwriting, into a comparative table, and appended significant related items. His final plan called for the main force to cross the Susquehanna River at or near Wyoming, Pennsylvania, and strike into the heart of the border region while a supporting column advanced from near Albany, New York. After Maj. Gen. Horatio Gates declined Washington's offer to command this expedition, citing health reasons, it was accepted by Maj. Gen. John Sullivan, who left his post at Providence, Rhode Island, to begin preparations at Middlebrook.

In a late-February reply to Mount Vernon manager Lund Washington's question about selling slaves, the general expressed his confidence in the eventual success of the American struggle for independence as well as his personal resolve, saying, "if we should ultimately prove unsuccessful (of which I am under no apprehension unless it falls on us as a punishment for our want of public, & indeed private virtue) it would be a matter of very little consequence to me, whether my property is in Negroes, or loan office Certificates, as I shall neither ask for, nor expect any favor from his most gracious Majesty, nor any person acting under his authority." By every measure, Washington remained indispensable to the Revolutionary cause.