Warburton Manor occupied a strategic site on the Potomac River and today it is the site of Fort Washington , designed by Pierre L'Enfant in 1814 .
George Washington spent his forty - third birthday at Warburton Manor .
Warburton Manor occupied a strategic site on the Potomac River and today Warburton Manor is the site of Fort Washington , designed by Pierre L'Enfant in 1814 .
George Washington spent his forty - third birthday at Warburton Manor .