The history of mortality reduction is spoken of in terms of three phases. In the first phase, from the mid-18th century to the mid-19th century, improved agricultural techniques played a large role. These techniques resulted in increased food supply, better nutrition, and economic growth. Emerging public health measures also played a role at this stage. The second phase ran from the end of the 19th century into the 20th. Public health became more important. People were given advice about personal health practices based on a growing understanding of the causes of disease. Because of high mortality rates in cities, urban centers started to deliver clean water (Figure 2) and remove waste. With the improved water supply, sewage, and general personal hygiene, there was a dramatic reduction in water- and food-borne diseases-typhoid, cholera, dysentery, and tuberculosis.