Final answer:
Trench Warfare did not affect U.S. soldiers in the Spanish-American War, as that was more characteristic of World War I. The Spanish-American War was marked by short battles and diseases taking more lives than combat.
Step-by-step explanation:
The aspect that did not affect U.S. soldiers in the Spanish-American War is c. Trench Warfare. While the U.S. soldiers faced many hardships during the Spanish-American War, such as rotten meat, spoiled canned goods, and wearing wool uniforms in tropical climates, trench warfare was not a significant feature of this conflict. Instead, trench warfare was more associated with World War I, occurring later. The Spanish-American War was characterized by quick battles, with disease being a bigger threat to soldiers than combat itself.