(1) With the population explosion that began during the1700s and continued through the 1800s, cities grew as rural people streamed into urban areas. This rapid growth was not due to larger families. In fact, families in most industrialized countries had fewer children. Instead, populations soared because the death rate fell and nutrition improved, thanks in part to improved methods of farming, food storage, and distribution. Medical advances and improvements in public sanitation also slowed death rates. (2) Since the 1600s, scientists had known of microscopic organisms, or microbes. Some scientists speculated that certain microbes might cause specific infectious diseases. Yet most doctors dismissed this germ theory. Not until 1870 did French chemist Louis Pasteur clearly show the link between microbes and disease. Pasteur went on to make other major contributions to medicine, including the development of vaccine. He also discovered a process called pasteurization that killed disease-carrying microbes in milk. Also, in the 1880s. the German doctor Robert Koch identified the bacterium that caused tuberculosis, a respiratory disease that claimed about 30 million human lives in the 1800s. (3) These successes brought about a soaring population and changed the face of cities forever with some undergoing rapid development. Together with growing wealth and industrialization, this altered the basic layout of European cities. City planners created spacious new squares and boulevards. They lined these avenues with government buildings, offices, department stores and theaters. The most extensive urban renewal, or rebuilding of the poor areas of a city, took place in Paris in the 1850s. Georges Haussmann, chief planner for Napoleon III, destroyed many narrow medieval streets full of poor housing. In their place, he built wide boulevards and grand public buildings. The project put many people to work, decreasing the threat of social unrest. The wide boulevards also made it harder for rebels to put up barricades and easier for troops to reach any part of the city. (4) Further improvements followed, with paved streets making urban areas much more livable. First, as lamps, and then electric streetlights illuminated the night, increasing safety. (5) Beneath the streets, sewage systems make cities a much healthier place to live. City planners knew that clean water supplies and better sanitation methods were needed to combat epidemics of cholera and tuberculosis. In Paris, sewer lines expanded from 139 kilometers in 1852 to more than 1200 kilometers by 1911. Th massive new sewer systems of London and Paris were costly, but they cut death rates dramatically. (6) By 1900, architects were using steel to construct tall buildings. American architects like Louis Sullivan pioneered a new structure, the skyscraper. In large cities, single-family middle-class homes gave way to multistory apartment buildings. (7) Despite these efforts to improve cities, urban life remained harsh for the poor. Some working-class families could afford better clothing, newspapers or tickets to a music hall. But they went home to small row houses in overcrowded neighborhoods. (8) In the worst areas, whole families were often crammed into a single room. Unemployment or sickness meant lost wages that could ruin a family. High rates of crime were a constant curse. Conditions had improved somewhat from the early days of the Industrial Revolution, but slums remained a fact of city life. (9) Despite their drawbacks, cities attracted millions. New residents were drawn as much by the excitement as by the opportunity for work. For tourists too, cities were centers of action. Music halls, opera houses and theaters provided entertainment for every taste. Museums and libraries offered educational opportunities. Sports, from tennis to boxing drew citizens of all classes. Few of these enjoyments were available in country villages.
Who rebuilt parts of Paris in the 1800s?