For regions and subpopulations of the US, this isn’t true. Philadelphia had ~25000 residents in 1790, and 5000 died in 1793 from yellow fever. That’s 1 in 5,

For regions and subpopulations of the US, this isn’t true. Philadelphia had ~25000 residents in 1790, and 5000 died in 1793 from yellow fever. That’s 1 in 5, and even NJ isn’t at 1 in 500 from COVID at this point. http://physics.bu.edu/~redner/projects/population/cities/philadelphia.html http://physics.bu.edu/~redner/projects/population/cities/phi... https://www.pbs.org/wgbh/americanexperience/features/fever-major-american-epidemics-of-yellow-fever/ https://www.pbs.org/wgbh/americanexperience/features/fever-m... I’m guessing other order-of-magnitude or greater events can be found in US history. Battlefield deaths were also atrocious before sulfa drugs and the like. Would normally be a bit pedantic, but the title does say “most difficult months in US health history”, a pretty high standard to meet.