The flag of the first American armed force, the Philadelphia City Cavalry.  The Light Horse of Philadelphia was established alongside the Continental Congress, as the first Colonial troop without ties to Britain.  They outfitted themselves and served the Colonies as a volunteer force under Congress.  They remain today as the oldest of Americas armed forces.  They fought valiantly under this banner at the Battles of Trenton, Princeton, Brandywine, and Germantown.  It was also the first flag to have featured the Thirteen Stripes, each representing a colony.