Geographical Risk of Disease Mortality during the US Civil War

Area of Science:

• Military History
• Epidemiology
• Public Health

Background:

• Infectious diseases caused a 2:1 mortality ratio over combat for Union soldiers during the US Civil War.
• Disease mortality exhibited significant geographical and demographic variations across regiments.

Purpose of the Study:

• To investigate the geographical patterns and demographic factors influencing US Civil War disease mortality.
• To identify correlations between pre-war living conditions and in-war disease susceptibility.

Main Methods:

• Utilized historical administrative records from the US Civil War to obtain disease mortality rates by state.
• Correlated disease casualties with soldier recruitment locations and 1860 Census data on occupations and population density.

Main Results:

• Higher disease mortality rates were observed in rural areas, particularly in southern and border states.
• A strong correlation existed between Civil War disease mortality and the proportion of farming occupations (R2 = 0.58).
• Elevated mortality was noted in Black and Native American soldiers, comparable to White soldiers from Confederate states.

Conclusions:

• Pre-war epidemiological isolation was associated with higher disease mortality.
• Urban living and prior military service correlated with lower disease mortality, likely due to acquired immunity.
• Geographical and occupational factors significantly influenced disease susceptibility during the US Civil War.