Davis first entered military service following the outbreak of the Spanish-American War in 1898, and later served as Professor of Military Science and Tactics at both Wilberforce University in Ohio and Tuskegee University in Alabama as well as serving tours of duty around the world.

Einstein, who was Jewish, was undertaking a visiting professorship at the California Institute of Technology in Pasadena when Adolf Hitler was appointed Chancellor on 30 January 1933.