Other venues were pressed into service — armories, gymnasiums and the Municipal Lodging House, which was converted from homeless shelter to sick bay for the duration of the epidemic. Hard-hit military installations like Camp Mills, Camp Dix and Camp Upton set up their own facilities. Upton hospitalized over 100 new patients every day between Sept. 15 and Oct. 9 — admissions peaked at 483 on Oct. 4 — in huge tent wards holding 900 infected; over 500 died at Upton alone.

On the slowing-the-spread front, Copeland also tackled what he considered the biggest and least-escapable dangers confronting still-healthy New Yorkers — the concentration and circulation of residents. Nothing packed bodies together as dangerously as the mass transit system. Subway and elevated cars almost certainly contained infected passengers who couldn’t afford to skip work and stay home. The most menacing moments of the day and night came during morning and evening rush hours. To de-concentrate the crush, Copeland arranged with businesses to stagger work hours. White-collar offices would open at 8:40 a.m. and close at 4:30 p.m.; wholesalers would start their days earlier, non-textile manufacturers would start later. Stores selling food and drugs were exempt.

Other obvious congestion points were schools and theaters, but where most American cities simply shut both down, Copeland went with a different strategy.

Schools, he reasoned, were often more sanitary than housing, particularly in the slums. New York City schools, moreover, boasted a well-established system of child health monitoring and care. Copeland, accordingly, kept the schools open. Under the direction of Dr. S. Josephine Baker, head of the Department of Health’s Bureau of Child Hygiene, school physicians inspected children each morning and sent sick students home. It worked — few children caught the disease — and in addition the schools handed out printed material on how to avoid the flu, for passing along to parents.

Theaters seemed a more unequivocal danger, but Copeland eschewed total closure. Many modern theaters were, after all, clean and well ventilated, and could be used to exhort audiences, urging them to adopt flu-prevention measures. On Oct. 11 Copeland announced that approved venues could stay open if they did not allow patrons to cough, sneeze or smoke. Dirty and stuffy “hole-in-the-walls,” as he called them, could be and were closed if they failed to meet sanitary standards.

Public health education campaigns, based on the city’s experience with mitigating infectious diseases, were another effort to slow the epidemic. By Sept. 24 at least 10,000 posters had been placed around the city in railway stations, elevated-train platforms, ferry landings, streetcars, store windows, police precinct houses, hotels and other public places. They explained how the virus was transmitted and instructed the citizenry to cover their coughs and sneezes, and to refrain from spitting. A small army of Boy Scouts was detailed to hand out printed cards to caught-in-the-act spitters, reading “You are in violation of the Sanitary Code.” They were backed up by the police, who rounded up New Yorkers caught spitting and brought them before courts in large numbers. On Oct. 4, 134 men were fined one dollar each at the Jefferson Market Court.

When it came to treating the infected, the terrible truth was that no effective medical intervention existed; doctors were virtually helpless. But nurses were not. The best that could be done for the afflicted was to provide them with soups, baths, blankets and fresh air, until the disease subsided or the patient died, which could happen within 24 hours of onset. This enormous task was taken on by a large army of women, commanded by the indefatigable Lillian Wald, who had pioneered the visiting-nurse service that would now be writ large.