On these rolling hills, George Washington's troops fought with the British for control of strategic territory near Philadelphia. The September 11, 1777, defeat had its victories, too: The Marquis de Lafayette saw his first military action here, witnessed the courage and determination of the Americans, and helped convince the French to form an alliance with the colonists. House tours of two Quaker farmhouses, which served as George Washington's headquarters and the quarters of Lafayette, are offered on the hour March to November. On-site are picnic areas and a visitor center with exhibits, dioramas, and a museum shop. Check the website for three driving tours.