Washington depended on telescopes to monitor British and American troop movements during the Revolution. His wartime correspondence contains frequent requests for and purchases of "[spy] glasses" and "pocket telescopes." In his will, Washington identified this handsome, three-draw, mahogany and brass spyglass by the well-known London optical instrument maker Henry Pyefinch as one "which constituted part of my equipage during the late War," and bequeathed it to his old friend, and cousin, Lawrence Washington. It was later returned to Mount Vernon by Mrs. Jefferson Davis in 1899.