What catastrophic event allowed John Snow to further prove his theory about cholera?

The 1854 cholera outbreak was pivotal for John Snow in proving his theory about the transmission of cholera through contaminated water. During this outbreak, Snow meticulously mapped the cases of cholera in London and observed a striking correlation between the locations of the cases and a particular public water pump on Broad Street. By conducting a detailed investigation, he demonstrated that those who used water from this pump were more likely to contract cholera, while those who sourced their water elsewhere remained largely unaffected.

This event provided Snow with empirical evidence to support his hypothesis that cholera was not spread via air, as was widely believed at the time, but rather through contaminated water. His groundbreaking work during the 1854 outbreak laid the foundation for modern epidemiology and significantly advanced public health measures, leading to improvements in water and sanitation systems. This outbreak served as a turning point in understanding infectious diseases and effectively showcased the vital link between water quality and public health.