Amherst, Jeffery Amherst, Baron, and Royal United Services Institute for Defence and Security Studies. "[Map showing rivers and forts in North America]." Map. Place of production not identified: Producer not identified, [ca. 1758]. Norman B. Leventhal Map & Education Center, https://collections.leventhalmap.org/search/commonwealth:hx11z162n (accessed April 19, 2024).