Conversation so far:
who was the military officer in charge of the research and development of the atomic bomb
Leslie Groves was the American army officer in charge of the Manhattan Project, which oversaw all aspects of scientific research, production, and security for the invention of the atomic bomb.
where did leslie groves go to college
Leslie Groves attended the University of Washington at Seattle and the Massachusetts Institute of Technology at Cambridge, Massachusetts, before entering the US Military Academy at West Point, New York
when did leslie groves graduate from the us military academy at west point, new york?
Leslie Groves graduated on November 1, 1918 from the US Military Academy at West Point, NY, 10 days prior to the armistice ending World War I.
when did leslie groves take charge of the manhattan project
Leslie Groves was selected as the Manhattan Project's head on September 17, 1942.

Question: when did the officer's charge end
Self-contained rewrite: when did leslie groves' charge of the manhattan project end