John K. Mahon and Romana Danysh, CMH 60-3: Infantry, Part I: Regular Army…
“ Once the nation had become a colonial power on account of the War with Spain, the study of war grew more important, and Americans turned to a review of what they had to fight with. It was clear that the Regular Army was too small to make up the whole defense and that stimulation of the militia was therefore necessary. As a result, one phase of the reform of 1903 was to replace the Federal militia law which had been on the books since 1792. This reform was particularly significant for the infantry because it comprised the bulk of the militia force. ”
