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.

The Military Service Act made all single men and childless widowers between the ages of 18 and 41 liable to be called up. It received royal assent on 27 January but was met with a protest demonstration of approximately 200,000 people in London’s Trafalgar Square, while by July almost 30% of those called up to fight had failed to appear.