In 1777 all three units participated in the Philadelphia campaign, taking part in the Battle of Brandywine, the Battle of Paoli and the Battle of Germantown. Remaining in Philadelphia over the winter and into 1778, the 64th and 2nd Grenadier Battalion formed part of the rearguard when Lieutenant-General Clinton evacuated the city in June 1778. Returning to New York, the 64th took part in several small operations. The Light company took part in the skirmish that became known as the Baylor Massacre.