GW had bought an English colt from Col. Bernard or Thomas Moore in Mar. 1759 for £17 10s. (General Ledger A description begins General Ledger A, 1750–1772. Library of Congress, George Washington Papers, Series 5, Financial Papers. description ends , folio 55).
“[Diary entry: 2 May 1760],” Founders Online, National Archives, https://founders.archives.gov/documents/Washington/01-01-02-0005-0005-0002. [Original source: The Diaries of George Washington, vol. 1, 11 March 1748 – 13 November 1765, ed. Donald Jackson. Charlottesville: University Press of Virginia, 1976, p. 275.]