A place where many people live and work is called a city. Cities are generally larger or more important than villages and towns. Cities around the world share similar advantages and problems. The largest cities in the world include Mumbai (Bombay), India; São Paulo, Brazil; Mexico City, Mexico; Tokyo, Japan; and New York City, United States. More than 8 million people live in each of these cities. Several million more people live in each city's surrounding suburbs. After New York City, some of the largest cities in the United States are Los Angeles, Chicago, and Houston. Each has more than 2 million people. Most cities, however, are much smaller. City featuresIn most cities thousands or even millions of people live in a relatively small area. That crowding can cause problems, including poverty, disease, and pollution. However, cities also have advantages over smaller towns. Cities have lots of businesses and jobs. Many cities have excellent schools and universities. Cities usually offer a variety of places for entertainment and relaxation—for example, museums, concert halls, theaters, parks, and sports arenas. Cities usually have a downtown, a central area with lots of stores and businesses. These areas are often the oldest parts of cities. Around many cities are suburbs, which tend to have more houses and apartments than businesses. Many people live in the suburbs and commute, or travel, to a city to work. People in cities rely on several forms of transportation: walking, bicycles, cars, taxicabs, and public transportation. Public transportation includes buses, trains, and subways. Subways are underground trains that do not clog the already crowded streets. City governmentLike countries and states, cities have a government. They often have a leader called a mayor. Many cities also have a group of lawmakers called a city council. A city's government has many responsibilities. It must provide fire and police protection. Other important services include water, power, garbage collection, and transportation. City schools, colleges, and libraries educate people of all ages. Many cities run hospitals or clinics. City leaders must decide where new factories, businesses, homes, parks, and roads can be built. They must also inspect public buildings to make sure they are safe. History of citiesThe earliest human beings were hunter-gatherers who moved around in search of food. As humans began to grow their own food and raise animals, many settled in villages. Life changed as villages grew into larger towns. Not everyone needed to be a farmer, so people could specialize in different types of work. They could then trade for things they needed, such as pottery or weapons. Early citiesPeople in Asia built the first cities about 7,000 years ago. Many began as centers of religion or trade. Early cities were similar to modern cities in many ways. They were larger than the surrounding villages and towns. They had large numbers of people, often crowded together. They had streets and large buildings. Ancient cities, however, often had walls around them to protect the residents from invaders. Over the centuries cities in Asia, North Africa, the Middle East, Europe, and the Americas grew in size and importance. Rome may have been the largest ancient city. Between 250,000 and 1 million people lived there. After invaders conquered Rome in the 5th century AD, however, its population fell. During the Middle Ages most cities in Europe were fairly small. The world's largest cities were mainly in China. Modern cities and suburbsIn the 19th century the growth of factories changed the way most people lived. Fewer people could make a living by farming. Large numbers of people began moving from farms to cities. They hoped to find jobs in factories. Millions of immigrants came to U.S. cities to look for work. Many people in cities lived in crowded, unhealthy conditions. At the same time architects discovered how to make buildings taller. In the late 19th and 20th centuries skyscrapers appeared in many cities. Between 1950 and 2000 the percentage of the world's population living in cities grew from 29 to 47 percent. As the inner cities became more crowded, many people moved to surrounding suburbs. Over time many stores and other businesses followed people out of the cities and into the suburbs. The downtown areas of many cities became poor and run-down. Future of citiesToday people in great numbers continue to move to cities to seek jobs. Some large cities have grown into megalopolises, or megacities. Megacities are highly populated areas that include several large cities and suburbs. For example, the part of the East Coast of the United States that includes Boston, New York City, Philadelphia, and Washington, D.C., could be called a megacity. Experts predict that more megacities will develop in the future. As the world's population keeps growing, cities will continue to be overpopulated. Homelessness and disease are problems for many city residents. The spreading out of cities, called urban sprawl, and pollution threaten the environment. City planners are working to solve these problems and to prevent new ones. |