Mainly, Johnson wrote this book to prove that one week in 1954 was one of the defining moments in what people today know as modern life. First, he proved that the first fateful week of September ultimately influenced the way cities organized themselves. Second, he proved that the events of the Broad Street Outbreak changed how disease was studied and viewed. Third, he proved that urban intelligence could come to understand a massive health crisis of which most people refused to see the truth. Ultimately, the week of the Broad Street outbreak impacted the ways cities organized themselves. Solutions for problems such as cholera helped urbanization in advancing sanitation standards. The Great Stink of 1858 forced authorities to confront the
However, the author claims that Snow’s map was revolutionary, writing, “Part of what made Snow’s map groundbreaking was the fact that it wedded state-of-the-art information design to a scientifically valid theory of cholera’s transmission. It was not the mapmaking technique that mattered; it was the underlying science that the map revealed.”

He merged innovative design with accurate and detailed data. To make this combination understood by all, he drew upon the Voronoi diagram, and in this, he was the first to do this in disease mapping, as he realized that his first map was vulnerable to miasmatic interpretation. He needed to show specific details such as foot traffic; portraying a concentration of deaths would not be enough. Snow’s design revolved around two shapes: the shape of the outbreak area itself, and the shape of best proximity to the Broad Street pump. Strangely, the shape of the outbreak followed the contours in the street, which it should not have done if it was miasma. In regard to design, the map was bird’s-eye view, but in regard to data, it was drawn from street-level knowledge. Snow made this map in the months after the outbreak to show people instantly and visually to show the deaths radiating from the pump. This map is seen as a founding document in medical detective work and epidemiology and public health. A number of great designers have pointed to it as a way that