Black troops as naturally resistant to tropical disease

U.S. military authorities treated Black soldiers as naturally more resistant to yellow fever and other tropical disease, influencing recruitment and assignments for service in Cuba during the Spanish-American War.

1 episode

Current understanding

Yellow fever is a viral disease transmitted by infected mosquitoes, and immunity follows vaccination or recovery from prior infection rather than racial ancestry. Malaria is caused by Plasmodium parasites transmitted by Anopheles mosquitoes; population differences in particular inherited traits do not make Black people generally immune to malaria or tropical disease. Black U.S. soldiers in Cuba contracted malaria and yellow fever in large numbers, directly contradicting the assumption of broad natural racial protection.

Consequences and human impact

During the Spanish-American War, U.S. military planning drew on the racial belief that Black soldiers were better adapted or naturally more resistant to tropical disease. The assumption affected both the organization of Black “Immune” volunteer regiments and assignments of Black regular troops to disease-stricken areas and hospital work in Cuba. Army experience quickly contradicted the theory: an official Army history records that half of 471 men of the 24th Infantry reporting for duty at Siboney contracted malaria or yellow fever.

How the consequences followed

The federal authorization for “Immune” troops did not itself state that Black people were racially immune to yellow fever. The racial proposition is documented instead in War Department and Army thinking and in how Black troops were recruited and assigned; the statute itself did not contain that racial claim.

The reported 50-percent figure combines malaria and yellow fever; it is not a yellow-fever-only infection rate.

Prior yellow-fever infection can create genuine lifelong immunity, and military planners also sought men thought to possess acquired immunity. That valid concept became entangled with the false assumption of broad innate racial resistance.

Black U.S. Volunteer Infantry regiments organized among the 1898 “Immune” regiments

50% of 471

men of the 24th Infantry at Siboney who contracted malaria or yellow fever according to official Army history

1898

racial disease-resistance assumptions shaped U.S. tropical-service decisions during the war

Quantitative figures are highlighted only when the cited evidence supports them. The scale of a related catastrophe is not automatically treated as a death toll caused solely by this belief.

Institutional episode

United States

1898Policy basis

In 1898 U.S. military authorities treated Black soldiers as especially suited to tropical service because they were believed to possess greater natural resistance to yellow fever and related diseases. The belief shaped the organization of Black “Immune” regiments and the assignment of Black regulars to sick-duty roles in Cuba. Official Army history records that 50 percent of 471 men of the 24th Infantry reporting at Siboney nevertheless contracted malaria or yellow fever, helping expose the supposed racial immunity as false.

Institutions

United States War Department
United States Army

Documented consequences

Racial assumptions influenced recruitment and organization of Black “Immune” volunteer regiments
Black regular troops were assigned to disease-stricken duties partly because of supposed natural resistance
Soldiers were exposed to tropical disease without the protection the racial theory implied
High malaria and yellow-fever morbidity among Black troops contradicted the institutional assumption

Institutional machinery

War Department and Army officials operated in a medical culture that often treated Black ancestry as conferring natural resistance to yellow fever and other tropical diseases. Four of the volunteer “Immune” regiments were organized as Black units, while Black regulars already serving in Cuba were also assigned duties on the assumption that they could withstand tropical disease better than white soldiers. The 24th Infantry, for example, was ordered to hospital duty at Siboney as yellow fever spread. Disease rates among the soldiers themselves soon undermined the supposed racial protection.

Sources and what they establish

Black Soldier, White Army — The 24th Infantry Regiment in KoreaU.S. Army Center of Military History
Buffalo Soldiers and the Spanish-American WarNational Park Service
Official NPS history stating that Black soldiers of the 24th Infantry served as nurses and hospital orderlies during the yellow-fever outbreak because of the stereotype that Black troops were physically better able to endure tropical conditions.
From Buffalo Soldier to Bath Attendant — Hugh HayesNational Park Service
Official NPS account noting that people inside and outside the War Department believed African American soldiers could handle Cuba's tropical climate better than white soldiers.
The Black “Immune” Regiments in the Spanish-American WarArmy Historical Foundation
Historical synthesis documenting General Orders No. 55 and No. 60, the four Black U.S. Volunteer Infantry “Immune” regiments and the erroneous belief that African Americans were naturally immune or especially suited to tropical disease environments.

Last reviewed: 24/08/2026