Street car conductor in Seattle not allowing passengers aboard without a mask during the Spanish Influenza Epidemic of 1918. Mass transit systems, with crowds of people in close quarters, were fertile venues for the spread of disease. Public health officials required passengers and employees wear masks as a precautionary measure to help them avoid contagion.

Street car conductor in Seattle not allowing passengers aboard without a mask during the Spanish Influenza Epidemic of 1918. Mass transit systems, with crowds of people in close quarters, were fertile venues for the spread of disease. Public health officials required passengers and employees wear masks as a precautionary measure to help them avoid contagion.