On Sept. 21, 1918, the Philadelphia Board of Health made influenza a mandatory reportable disease, as the epidemic began to increase in the city.

Full of patriotism and believing that the epidemic just starting to rage across many Eastern cities in the United States was overblown, civic leaders and some 200,000 Philadelphians amassed along Broad Street on September 28 to cheer on the long parade. The decision, however, would turn out to be a fateful one.