1. On 11 Sept. in a general engagement at Chadd's Ford on Brandywine Creek, Washington had, in his own words, “been obliged to leave the enemy masters of the field” and to retreat first to Chester and then to the eastern bank of the Schuylkill at Germantown. On the 12th JA had moved from Capt. Duncan's in Walnut Street to Rev. Mr. Sproat's in Third Street, for what was to prove a short stay and a precipitant departure. On the day he wrote the present letter Congress resolved that if it should prove necessary to leave Philadelphia, “Lancaster shall be the place at which they shall meet.” A warning received early on the morning of the 19th that Howe was in possession of a ford over the Schuylkill caused the members to depart that day. They sat at Lancaster, however, only on the 27th and adjourned to meet at York on the 30th. See JA to AA, 30 Sept., below; to Speaker of Massachusetts House of Representatives, 15 Jan. 1778, NN: Emmet Coll.; Diary and Autobiography , 2:262–267; Washington, Writings, ed. Fitzpatrick, 9:207; JCC , 8:742, 754–756.