Lancaster Septemr 26th 1777
Sir
As the future safety of Philadelphia and the public good so greatly depend upon preventing the enemies Fleet from getting up to Town and succoring the Army, you are desired to co-operate in the most full and friendly manner with the Other Land and Sea forces both of the Continental and the State of Pennsylvania in effecting this valuable purpose. It is expected that you exert every art that valour, vigilance and address can suggest to you, as well as to prevent the enemy from Philadelphia possessing themselves of the Fort, as to keep the British Fleet from getting up. If there should be a probability of either provisions or ammunition failing you, let timely care be taken to get supplied from General Washington who with his Army will be in the neighbourhood of Philadelphia above the City. If the Fort and the passage of the River is bravely and properly defended, the possession of Philada will probably turn out to be the ruin of the British Army. —
Your established reputation for valour makes it unnecessary to say that brave minds should never despair, and that every thing is to be hazarded where the public good require it. You and the brave American forces with you, will therefore keep the defences on the River Delaware to the last extremity. But, if every resource of valour and Skill should fail you, and it becomes absolutely impossible to hold out any longer, you are then to push with the Continental Vessels as far as they can Swim up the River, and having defended them there as long as possible, they must all be destroyed rather than suffer them to fall into the enemies hands. If it should be found that Fort Mifflen must be given up, you are then to use your utmost endeavours to bring off the garrison and convey the Troops to a place of safety. Congress has already determined that in defending the Delaware the Continental Marine Officers shall be under command of the Commodore of this State, and you are accordingly to observe and pay due regard to that Resolve. Wishing you the most honourable Success We are Sir [&c.]