“To George Washington from Maj. Gen. John Armstrong, 17 September 1777 [letter not found],” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/03-11-02-0245. [Original source: The Papers of George Washington, Revolutionary War Series, vol. 11, 19 August 1777 – 25 October 1777, ed. Philander D. Chase and Edward G. Lengel. Charlottesville: University Press of Virginia, 2001, p. 252.]