Complex sentence: It was administered by the War Department for the benefit of military members, officers of the Public Health Service, and honorably discharged veterans, who suffered from such diseases as the waters of the hot springs had an established reputation in benefiting.
Split into simpler sentences: It was administered by the War Department for the benefit of military members, officers of the Public Health Service, and honorably discharged veterans. The waters of the hot springs had an established reputation in benefiting.