John Snow’s report on the causes of cholera provided yet more evidence of the dangers of filthy cities. Cities had always been unhealthy places to live, generally with a higher death rate than birth rate, but fixing them just wasn’t the focus of an agricultural world economy. The Industrial Revolution in the 1700s brought more people to the cities, and suddenly, cities had to grow in order to maintain the vastly expanded manufacturing and shipping operations of the new era.
Edwin Chadwick published a report about the sewage in city streets and clearly explaining the need to remove it. His report led to legislation that created local health boards and drove the construction of complex sewer systems. These sewers were massive, expensive undertakings that, even today, remain the foundation of many large modern cities. They reduced diseases across the board and saved countless human lives, part of a legacy that John Snow would be proud of.