History is filled with battles, campaigns, and wars in which commanders did not fully account for the effects of climate and pathogens within their operational environment. Today, commanders sometimes minimize how unfamiliar climates and pathogens can impact the health and well-being of their soldiers, but more importantly, how these variables may adversely affect their overall mission. By analyzing and accounting for the climate of the operational environment, commanders and their staffs will be able to better mitigate diseases and non-battle injuries (DNBI) within their formations, which can help maintain or increase their relative combat power, tempo, and operational reach. This is especially true when armies are operating in new environments known to be insalubrious and disease-ridden. This monograph examines Major General Nathaniel Banks's Port Hudson campaign in 1863, which provides a useful case study about how climatic factors, including local disease and environments, adversely impacted a commander's ability to arrange tactical actions in time, space, and purpose. While Banks ultimately succeeded in capturing Port Hudson, it came at a high cost of losing a third of his men, which four-thousand of them were attributed to climatic factors. This led Banks's army to culminate and forced him to reconstitute before future operations.

Approved for public release; distribution is unlimited. The opinions and conclusions expressed herein are those of the student-authors and do not necessarily represent the views of the U.S. Army Command and General Staff College or any other governmental agency. (References to these studies should include the foregoing statement.)