Because of a heroic rear guard action, Wayne was able to escape the Battle of Paoli with 1900 men. The survivors of Paoli never forgot the horror of that night. Indeed, it inspired them to fight with a vengeance at the Battle of Germantown, where British officers recounted hearing the Americans shouting, "Remember Paoli!" in the fury of the battle. Using the lessons learned at Paoli, in1779 Wayne and his men would make their own midnight attack with bayonets fixed, to capture the British fortress at Stony Point, New York. Finally, Wayne and many of his Pennsylvanians survived the war and were present at Yorktown for the British surrender in 1781.
Before the Battle of Paoli on September 20, there were warning signs that the British were aware of Wayne's mission. On the morning of September 19, shortly after arriving at the Paoli Tavern (located a mile and a half east of this camp), Wayne wrote to Washington, "I believe [Howe] knows nothing of my Situation as I have taken every precaution to Prevent any intelligence getting to him." Not two hours later, Wayne " ? in the Afternoon changed the position of his Troops on understanding the Enemy intended to attack us, and took post on some high Ground above Warren Tavern on the Lancaster Road." This maneuver brought Wayne's troops to this campsite.
Later on September 19, Wayne suddenly evacuated this camp. No American sources explain why, but one of General Howe's aides wrote that British light Infantry and riflemen " ? found General Wayne two and a half miles behind us, and they had almost surrounded him when fate intervened. Two drunken Englishmen fired at a picket, which touched off an alarm, and permitted their escape, though in great confusion." Wayne himself later referred to the evacuation but gave no explanation for it.
Colonel Thomas Hartley, the third in command, reported that "an Old Man by the name of Jones" came into the camp after dark on September 20, three hours before the attack. Mr. Jones had been at the Paoli Tavern and had seen a servant who had been in the British camp and heard soldiers talking about attacking Wayne, "that they would have done it the night before had he not changed his ground." In response to Jones's information, Wayne increased the pickets and sent out horse patrols. The Pickets were established as follows:
Picket #1: "One Mile from Camp near the Paoli." [Route 30 and Cedar Hollow Road, Paoli]
Picket #2: "One Half Mile in the Rear of our Right." [Paoli Pike east of Warren Avenue, Malvern]
Picket #3: "Immediately on the Right of the Artillery." [Channing Avenue north of 1st Avenue, Malvern]
Picket #4: " ? of a Mile to the Right in front on the Lancaster Road." [Old Lincoln Highway and Longford Avenue, Malvern]
Picket #5: "One Mile from Camp at the Warren." [Old Lancaster Road near Warren Tavern, Malvern]
Picket #6: "at the fork of two Roads on our left." [Sugartown, 100 yards north of King Road, Malvern]
It was the horse patrols sent out after Mr. Jones's warning that first spotted the British advance on Swedesford Road, and returned to camp with the alert.
Sidebar: Was Wayne Negligent?
After the Battle of Paoli, rumors circulated among Wayne's officers that he had received warnings about the attack, but failed to take adequate precautions. When Wayne was confronted about this, he wrote to Washington and demanded a court martial to clear his name. A Court of Inquiry did not satisfy Wayne, so a full court martial was held in late October 1777. The court martial found Wayne "not guilty" of negligence, and stated that he "did everything that could be expected from an active, brave, and vigilant officer, with the orders he then had. The Court do acquit him with the highest honor."