In 1900, what was the leading cause of death in the United States?

• A. Pneumonia/influenza
• B. Heart disease
• C. Tuberculosis
• D. Cancer

Answer: (A)

The main idea here is how causes of death were distributed at the turn of the century. In 1900, deaths from infectious respiratory diseases were the dominant threat. Pneumonia and influenza killed more people than any other cause because there were no antibiotics, vaccines, or effective treatments for these infections, and living conditions in many cities were crowded and unsanitary. This made respiratory infections widespread and deadly.

Tuberculosis was also a major killer and often ranked near the top, but pneumonia and influenza still topped the list. Heart disease and cancer existed as causes of death, but they were less common than infectious diseases at that time, partly because life expectancy was shorter and people often did not live long enough to develop these chronic conditions at the high rates seen later in the century.

As public health measures improved, vaccines, antibiotics, better sanitation, and nutrition reduced deaths from infections, while life expectancy increased and chronic diseases became more prominent, shifting the leading causes of death in the years that followed.