Final answer:
The Vietnam War was called "A Poor Man's War" because the majority of the soldiers sent to fight in Vietnam were from less privileged economic backgrounds.
Step-by-step explanation:
The Vietnam War was called "A Poor Man's War" because many of the young men being drafted and sent to Vietnam were from lower economic classes. The draft system allowed young men from well-off families who were in college to be automatically excused, so the majority of the soldiers fighting in Vietnam were from less privileged backgrounds. This led to the perception that the war was primarily being fought by working-class individuals.