When World War II started, he was called up as a colonel and assigned to the United States Military Academy. The head of the physics department there, Gerald Counts, was reassigned to Europe, and Bartlett stepped in as acting head of the department.
When World War II began, he was called up as a colonel and assigned to the United States Military Academy. Following the transfer of Gerald Counts, the head of the physics department, to Europe, Bartlett took over as acting head of the department.