Volume 15 of the ""Revolutionary War Series"" documents a period that includes the Continental Army's last weeks at Valley Forge, the British evacuation of Philadelphia, and the Battle of Monmouth Court House. The volume begins with George Washington's army at Valley Forge, Pennsylvania, celebrating the new alliance between the United States and France. Washington joined in the festivities but did not become complacent, and as the celebrations ended he redirected his attention to winning the war. Over the next few weeks Steuben drilled the soldiers incessantly while Washington and Congress conducted a much-needed overhaul of the army's structure and administration. The benefits of the training became apparent on the evening of 19 May, when a large detachment under Major General Lafayette deftly evaded an attempted British entrapment at Barren Hill, Pennsylvania. Yet Washington had little time to ponder his troops' new efficiency and discipline. The British evacuation of Philadelphia began on the morning of 18 June, as General Henry Clinton's army crossed the Delaware River and marched east-northeast across New Jersey toward a rendezvous with British transport ships at Sandy Hook. The Continentals at first pursued at a respectful distance, but on 24 June Washington overrode the objections of some of his general officers and sent forward a detachment of 5,600 men under Major General Charles Lee to seek opportunities for attack. That opportunity came at Monmouth Court House on 28 June, in the midst of a brutal heat wave that claimed the lives of dozens of soldiers on both sides. Lee's attack at first caught the British by surprise, but General Cornwallis formed up his troops for a counterattack and easily drove Lee's detachment from the field. Washington meanwhile hurried forward with the remainder of his army and encountered Lee and his fleeing troops a short distance west of Monmouth Court House. Berating the dejected Lee for failing to follow orders, Washington stopped the retreat and formed a new line of defense. The remainder of the battle consisted of a series of closely fought encounters as Cornwallis attempted and failed to dislodge the Americans from their positions. That night the British withdrew east with the rest of Clinton's army, marching to Sandy Hook and thence sailing to New York, leaving Washington and his army in possession of the battlefield. Clinton considered the battle a successful delaying action; Washington, with equal certainty, declared it a glorious American victory.