From George Washington to David Waterbury, 21 July 1781

The Army will make a Movement this Evening—You will march your Corps on the same route, & in such time & Manner & as to be at East Chester between daybreak & sunrise; as directed in my Letter of the 14th. Your Troops should be supplied (if possible) with three days cooked provisions, and the Movement of the Army as well as of your Troops must be kept a secret until the Moment you march.

In order to prevent the Enemy from obtaining any intelligence whatever from us; I have ordered small parties to waylay all the Roads from the North River to East Chester. I must request you will send an Active Subaltern, & 20 Men with good Guides, early this afternoon across the Feilds & Woods from your Encampment to some good position for an Ambuscade, on the side of the road leading from New Rochel to East Chester, as near the latter as may without hazard of discovery, this party must remain perfectly concealed, with Orders to apprehend all Persons going towards Kings Bridge. It is essential your Party should not be seen by any Inhabitant, as this might frustrate the very object of our precautions. You will be convinced, Sir by your own experience & good Sense that the profoundest secrecy is absolutely necessary in all Military Matters, & in no instance more indespensably so, than in Movements towards the Enemy’s Lines. I am Sir with great regard.