The Earliest Cities

Early cities arose in a number of regions, and are thought to have developed for reasons of agricultural productivity and economic scale.

Learning Objectives

Summarize the various beginnings of cities, from centers of agriculture to areas of protection, and the factors they need to be successful

Key Takeaways

Old WorldNeolithic Revolutionurbanism

Several regions developed early cities, from Mesopotamia to Asia to the Americas.Several cities were founded in Mesopotamia after the Neolithic Revolution, around 7500 BCE.Eridu, Uruk, and Ur were three Mesopotamian cities.The Indus Valley and ancient China also had cities at this time. .Cities flourished in ancient America between the 30th century BCE and the 18th century BCE in the Andes and Mesoamerica. It was effectively astronomy to study visible-light spectra for much of the 20th century.A number of exciting breakthroughs in recent decades have diverted attention from this field.Modern astronomy rests on this bedrock nonetheless.

The Formation of Cities

Why did cities form in the first place? There is insufficient evidence to assert what conditions gave rise to the first cities, but some theorists have speculated on what they consider pre-conditions and basic mechanisms that could explain the rise of cities. Agriculture is believed to be a pre-requisite for cities, which help preserve surplus production and create economies of scale. The conventional view holds that cities first formed after the Neolithic Revolution, with the spread of agriculture. The advent of farming encouraged hunter-gatherers to abandon nomadic lifestyles and settle near others who lived by agricultural production. Agriculture yielded more food, which made denser human populations possible, thereby supporting city development. Farming led to dense, settled populations, and food surpluses that required storage and could facilitate trade. These conditions seem to be important prerequisites for city life. Many theorists hypothesize that agriculture preceded the development of cities and led to their growth.

A good environment and strong social organization are two necessities for the formation of a successful city. A good environment includes clean water and a favorable climate for growing crops and agriculture. A strong sense of social organization helps a newly formed city work together in times of need, and it allows people to develop various functions to assist in the future development of the city (for example, farmer or merchant). Without these two common features, as well as advanced agricultural technology, a newly formed city is not likely to succeed.

Cities may have held other advantages, too. For example, cities reduced transport costs for goods, people, and ideas by bringing them all together in one spot. By reducing these transaction costs, cities contributed to worker productivity. Finally, cities likely performed the essential function of providing protection for people and the valuable things they were beginning to accumulate. Some theorists hypothesize that people may have come together to form cities as a form of protection against marauding barbarian armies.

Preindustrial Cities

Preindustrial cities had important political and economic functions and evolved to become well-defined political units.

Learning Objectives

Examine the growth of preindustrial cities as political units, as well as how trade routes allowed certain cities to expand and grow

Key Takeaways

lordrural obligationsPreindustrial cities

Cities as Political Centers

While ancient cities may have arisen organically as trading centers, preindustrial cities evolved to become well defined political units, like today’s states. During the European Middle Ages, a town was as much a political entity as a collection of houses. However, particular political forms varied. In continental Europe, some cities had their own legislatures. In the Holy Roman Empire, some cities had no other lord than the emperor. In Italy, medieval communes had a state-like power. In exceptional cases like Venice, Genoa, or Lübeck, cities themselves became powerful states, sometimes taking surrounding areas under their control or establishing extensive maritime empires. Similar phenomena existed elsewhere, as in the case of Sakai, which enjoyed a considerable autonomy in late medieval Japan.

For people during the medieval era, cities offered a newfound freedom from rural obligations. City residence brought freedom from customary rural obligations to lord and community (hence the German saying, “Stadtluft macht frei,” which means “City air makes you free”). Often, cities were governed by their own laws, separate from the rule of lords of the surrounding area.

Trade Routes

Some cities did not become major urban centers.In the early modern era, larger capital cities took advantage of new trade routes and grew even larger.Since the emergence of an Atlantic trade, while the city-states of the Mediterranean and Baltic seas languished from the 16th century, Europe's larger capitals benefitted from the growth of commerce.At the beginning of the 19th century, London was the world's largest city with a population of over a million, while Paris was comparable to well-developed regional capitals like Baghdad, Beijing, Istanbul, and Kyoto.Although most towns remained far smaller than they are today-around two dozen places in the world had more than 100,000 inhabitants in 1500.In 1700 there were fewer than 40, but there were 300 by 1900.The population of a small city in the early modern period could be as few as 10,000.

Industrial Cities

During the industrial era, cities grew rapidly and became centers of population growth and production.

Key Takeaways

industrial citiesindustrial era

Slum in Glasgow, 1871: An example of slum life in an industrial city.

During the industrial era, cities grew rapidly and became centers of population and production. The growth of modern industry from the late 18th century onward led to massive urbanization and the rise of new, great cities, first in Europe, and then in other regions, as new opportunities brought huge numbers of migrants from rural communities into urban areas. In 1800, only 3% of the world’s population lived in cities. Since the industrial era, that figure, as of the beginning of the 21st century, has risen to nearly 50%. The United States provides a good example of how this process unfolded; from 1860 to 1910, the invention of railroads reduced transportation costs and large manufacturing centers began to emerge in the United States, allowing migration from rural to urban areas.

Rapid growth brought urban problems, and industrial-era cities were rife with dangers to health and safety. Rapidly expanding industrial cities could be quite deadly, and were often full of contaminated water and air, and communicable diseases. Living conditions during the Industrial Revolution varied from the splendor of the homes of the wealthy to the squalor of the workers. Poor people lived in very small houses in cramped streets. These homes often shared toilet facilities, had open sewers, and were prone to epidemics exacerbated by persistent dampness. Disease often spread through contaminated water supplies.

In the 19th century, health conditions improved with better sanitation, but urban people, especially small children, continued to die from diseases spreading through the cramped living conditions. Tuberculosis (spread in congested dwellings), lung diseases from mines, cholera from polluted water, and typhoid were all common. The greatest killer in the cities was tuberculosis (TB). Archival health records show that as many as 40% of working class deaths in cities were caused by tuberculosis.

The Structure of Cities

Urban structure is the arrangement of land use, explained using different models.

Learning Objectives

Analyze, using human ecology theory, the similarities and differences between the various urban structure models, such as grid model, sectoral model and concentric ring model, among others

Key Takeaways

central business districturban open spaceHuman Ecology

Urban Structure Models


In grid models, land is divided by streets intersect at right angles, forming a grid. Grid plans are more common in North American cities than in Europe, where older cities tend to be build on streets that radiate out from a central square or structure of cultural significance. Grid plans facilitate development because developers can subdivide and auction off large parcels of land. The geometry yields regular lots that maximize use and minimize boundary disputes. However, grids can be dangerous because long, straight roads allow faster automobile traffic. In the 1960s, urban planners moved away from grids and began planning suburban developments with dead ends and cul-de-sacs.

Concentric Ring Model

Ernest Burgess proposed the concentric ring model of growth in Chicago in 1924.In it, humans and cities are compared to ecosystems, with adaptation and assimilation processes.Based on their class, culture and assimilation, city residents naturally sort themselves into ecological niches.A zone of transition (B) encircles the CBD, which consists of poor-quality housing and industrial facilities.Three rings (C) are full of housing for the working class - the zone of independent workers' homes.Middle-class houses are located in the fourth ring (D).In the outer ring, or commuter zone, are residential suburbs.

Toronto’s Central Business District: Skyscrapers populate Toronto’s central business district


Concentric Zone Model: The Concentric Ring Model described the city as a series of concentric rings, each home to a different group and social function.

A question has been raised about the model's general applicability.It describes American geography in which inner cities are poor and suburbs are rich - elsewhere, the reverse is the case.These "zones" have become blurred in new, western U.S. cities like Los Angeles due to advances in transportation and communication.Furthermore, the model fails to take into account topological and physical features of the landscape.Chicago's concentric rings are semicircular, interrupted by Lake Michigan.


The economist Homer Hoyt adapted the concentric ring model in 1939, postulating that cities should develop into wedge-shaped sectors rather than rings.In some parts of a city there are more activities to be found, either because of geography or environmental considerations.In line with their expansion outward, these activities grow into city sectors.Hoyt's sectoral model has been criticized for ignoring physical features and new transportation patterns that limit or direct growth, similar to the concentric ring model.


Hoyt’s Sectoral Model of Urban Growth: In Hoyt’s model, cities grow in wedge-shaped sectors radiating from the center.

Multiple Nuclei

In 1945, the multiple nuclei theory was developed to explain city formation in the post-automobile era.Since more people own cars, they are mobile, allowing for a specialization of regional centers.Most cities have more than one center for activity.Nodes are attracted to some activities and others avoid them.The downtown area near a university may attract educated residents, pizzerias, and bookstores, whereas the area around an airport may attract warehouses and hotels.Activities incompatible will not cluster together.

Irregular Pattern

The irregular pattern model is used to explain urban structure in the Third World.This study attempts to model the lack of planning that exists in many rapidly built Third World cities.The blocks of this model are not in a fixed order; the urban structure does not correlate with a city center or CBD.

Alternate Uses of “Urban Structure”

Urban structure can also refer to urban spatial structure; the arrangement of public and private space in cities and the degree of connectivity and accessibility. In this context, urban structure is concerned with the arrangement of the CBD, industrial and residential areas, and open space.

A city’s central business district (CBD), or downtown, is the commercial and often geographic heart of a city. In North America, this is referred to as “downtown” or “city center. ” The downtown area is often home to the financial district, but usually also contains entertainment and retail. CBDs usually have very small resident populations, but populations are increasing as younger professional and business workers move into city center apartments.

An industrial park is an area zoned and planned for the purpose of industrial development. They are intended to attract business by concentrating dedicated infrastructure to reduce the per-business expenses. They also set aside industrial uses from urban areas to reduce the environmental and social impact of industrial uses and to provide a distinct zone of environmental controls specific to industrial needs.

Urban open spaces provide citizens with recreational, ecological, aesthetic value. They can range from highly maintained environments to natural landscapes. Commonly open to public access, they may be privately owned. Urban open spaces offer a reprieve from the urban environment and can add ecological value, making citizens more aware of their natural surroundings and providing nature to promote biodiversity. Open spaces offer aesthetic value for citizens who enjoy nature, cultural value by providing space for concerts or art shows, and functional value—for example, by helping to control runoff and prevent flooding.

The Process of Urbanization

Urbanization is the process of a population shift from rural areas to cities, often motivated by economic factors.

Learning Objectives

Analyze the proces of urbanization and its effects on economics and the environment in society

Key Takeaways

suburbanizationrural flighturbanizationcounterurbanizationgentrification

Urbanization and rural flight

Urbanization is the process of a population shift from rural areas to cities. During the last century, global populations have urbanized rapidly:

One projection suggests that, by 2030, the proportion of people living in cities may reach 60%.

Rural and Urban World Population: Over time, the world’s population has become less rural and more urban.

Industrialization and urbanization tend to be positively correlated.Because industrialization promises greater job opportunities, rural citizens from rural parts of the country will move to urban areas to pursue greater economic rewards. The term "rural flight" is also used to describe urbanization.In modern times, such a flight occurs particularly in areas that have undergone industrialization in agriculture-when fewer workers are required to bring the same amount of agricultural output to market-and where related agricultural services and industries are also consolidated.The negative impact of these factors does not merely negatively affect small- and middle-sized farms, but also reduces the rural labor market's size.The population decline leads to the loss of rural services (such as business enterprises and schools), which in turn leads to the loss of more people as they leave to seek these features. Cities grow as more and more people leave the countryside to live in cities.Migration from rural areas to urban areas was largely to blame for the growth of Chicago in the late nineteenth century and Mumbai a century later.Growing urban populations are quite common in developing countries in particular. The process of urbanization is largely a result of individual and corporate efforts to cut travel time and expenses while improving access to jobs, education, housing, entertainment, and transportation.Individuals and families can take advantage of proximity, diversity, and market competition by living in cities.In addition to having a highly concentrated population, urban areas can also have a more diverse social structure, allowing individuals to find like-minded people.

Economic and Environmental Effects of Urbanization

City growth and urbanization have significant economic and environmental effects.The growing populations of cities raise the demand for goods and services of all kinds, thereby driving up those prices, as well as the price of land.Working class residents may be priced out of the housing market as land prices rise. This is called gentrification. CBDs are the commercial and geographic center of cities.North America calls this "downtown" or the "city center.".There is often a financial district in the downtown area, but there are also usually entertainment areas and retail stores.CBDs usually have very small populations, but the number of residents is rising as young professionals and business people move into city center apartments.

Suburbanization and Counterurbanization

Recently in developed countries, sociologists have observed suburbanization and counterurbanization, or movement away from cities. These patterns may be driven by transportation infrastructure, or social factors like racism. In developed countries, people are able to move out of cities while still maintaining many of the advantages of city life (for instance, improved communications and means of transportation). In fact, counterurbanization appears most common among the middle and upper classes who can afford to buy their own homes.

Race also plays a role in American suburbanization. During World War I, the massive migration of African Americans from the South resulted in an even greater residential shift toward suburban areas. The cities became seen as dangerous, crime-infested areas, while the suburbs were seen as safe places to live and raise a family, leading to a social trend known in some parts of the world as “white flight. ” Some social scientists suggest that the historical processes of suburbanization and decentralization are instances of white privilege that have contributed to contemporary patterns of environmental racism.

In the United States, suburbanization began in earnest after World War II, when soldiers returned from war and received generous government support to finance new homes. Suburbs, which are residential areas on the outskirts of a city, were less crowded and had a lower cost of living than cities. Suburbs grew dramatically in the 1950s when the U.S. interstate highway system was built, and automobiles became affordable for middle class families. Around 1990, another trend emerged known as counterurbanization, or “exurbanization”. The wealthiest individuals began living in nice housing far in rural areas (as opposed to forms).

Suburbanization may be a new urban form.Rather than densely populated centers, cities may become more spread out, composed of many interconnected smaller towns. Interestingly, the modern U.S. experience has gone from a largely rural country, to a highly urban country, to a country with significant suburban populations.

U.S. Urban Patterns

The U.S. Census Bureau classifies areas as urban or rural based on population size and density.

Learning Objectives

Discuss the different ways governments and society define the term “urban”

Key Takeaways

population density

Different international, national, and local agencies may define “urban” in various ways. For example, city governments often use political boundaries to delineate what counts as a city. Other definitions may consider total population size or population density. Different definitions may also set various thresholds, so that in some cases, a town of just 2,500 may count as an urban city, whereas in other contexts, a city may be defined as having at least 50,000 people. Other agencies may define “urban” based on land use: places count as urban if they are built up with residential neighborhoods, industrial sites, railroad yards, cemeteries, airports, golf, and similar areas. Using this sort of definition, in 1997, the U.S. Department of Agriculture tallied over 98,000,000 acres of “urban” land.

In spite of these competing definitions, in the United States “urban” is officially defined following guidelines set by the U.S. Census Bureau. The Census Bureau defines “urban areas” as areas with a population density of at least 1,000 people per square mile and at least 2,500 total people. Urban areas are delineated without regard to political boundaries. Because this definition does not consider political boundaries, it is often used as a more accurate gauge of the size of a city than the number of people who live within the city limits. Often, these two numbers are not the same. For example, the city of Greenville, South Carolina has a city population under 60,000 and an urbanized area population of over 300,000, while Greensboro, North Carolina has a city population over 200,000 and an urbanized area population of around 270,000. That means that Greenville is actually “larger” for some intents and purposes, but not for others, such as taxation, local elections, etc.

As of December, 2010, about 82% of the population of the United States lived within the boundaries of urbanized area. Combined, these areas occupy about 2% of the land area of the United States. The majority of urbanized area residents are suburbanites; core central city residents make up about 30% of the urbanized area population (about 60 million out of 210 million). In the United States, the largest urban area is New York City, with over 8 million people within the city limits and over 19 million in the urban area. The next five largest urban areas in the United States are Los Angeles, Chicago, Washington, D.C., Philadelphia, and Boston.


American urban areas by size: This map shows major urban areas in America.

Key Takeaways

white flightex-urbscounterurbanization

The rural rebound is the movement from urban areas to rural and suburban areas.Urbanization usually occurs along with modernization. However, many cities in the most developed countries have begun to lose populations.Researchers in the 1970s observed that rural populations were actually increasing faster than urban populations, a phenomenon they dubbed the rural rebound.As a result of a recession that particularly affected farmers in the 1980s, this trend reversed.Rural populations also appeared to be gaining in the 1990s at the expense of urban ones.Since 1950, about 370 cities worldwide with more than 100,000 residents have lost over ten percent of their population, and about 25 percent of these depopulating cities are in the United States. Most participants of the so-called rural rebound migrated into new, rapidly growing suburbs in lieu of moving to rural areas.


As a general term, suburbanization refers to moving from cities to surrounding areas. .There have been several new terms invented to describe these new suburb towns, such as ex-urban and edge cities.Suburbanization also has a racial component. As a result of African American migration during World War I, residents moved to suburban areas in even greater numbers.During the twentieth century, most of the population lived in the cities, viewed as dangerous and crime-ridden, while the suburbs were considered safe and good places to raise a family, leading to a phenomenon known as "white flight".Several social scientists have argued that suburbanization and decentralization were historically linked to white privilege, and contributed to the present-day environmental racism we see.After World War II, many soldiers returned to the US with generous government-funded housing packages, sparking the beginning of suburbanization in earnest.Compared to cities, suburbs are less crowded, less expensive, and less crowded.After Interstate highways were built in the 1950s, and automobiles became affordable for middle class families, suburban populations rapidly grew. A new trend began around 1990 known as counterurbanization, or exurbanization.The wealthiest began living in nice houses in rural areas (rather than in big cities).

White Flight

Among the many explanations proposed by sociologists for counterurbanization, a major debate involves whether suburbanization is due to white flight.In the mid-20th century, white flight was coined to describe the suburbanization of large numbers of whites from racially mixed urban areas into more racially homogeneous suburbs.During the first half of the twentieth century, discriminatory housing policies often prevented blacks from relocating to suburbs: lending institutions made it difficult for blacks to get mortgages, and local communities used restrictive covenants to exclude minorities. The flight of whites during this time period significantly contributed to urban decay, a process whereby a city, or part of a city, falls into disrepair and decay.Depopulation, abandoned buildings, unemployment, crime, and a barren, uninviting environment are signs of urban decay.In cities, exodus of middle-class people led to a drain on tax bases, exacerbating urban decay caused in part by the loss of industrial and manufacturing jobs, which had moved overseas or to rural areas where labor was cheaper. Suburbanization has also been extended to include migrations from urban to rural areas and outlying areas.Demographers have also labeled the rural rebound, and the newest waves of suburbanization, as an ethnic balkanization phenomenon, in which ethnic groups (not just whites) sort themselves into racially homogeneous communities.However, these phenomena are not under the control of the same restrictive policies, laws, and practices that drove white flight in the first half of the 20th century.

A Suburban Neighborhood: Suburban neighborhoods often feature large, manicured lawns.

Key Takeaways

smart growthurban renewalNew Urbanism

The urban environment is dynamic - it grows, shrinks, and changes.Sociologists have developed different theories to explain urban population change.

Growth Machine Theory

The growth-machine theory of urban growth holds that city growth is driven by a coalition of interest groups benefiting from continuous expansion and growth.According to Molotch, growth machine theory turned the conventional approach to land use in cities upside-down in 1976. The influx of whites during this period exacerbated the urban decay process, whereby a city or part of a city falls into disrepair and decay.Urban decay manifests as depopulation, abandoned buildings, high unemployment, crime, and a desolate, inhospitable landscape.Due to white flight, cities lost a significant portion of their tax bases as middle-class people left, contributing to urban decay due to a loss of industrial and manufacturing jobs that were relocated to rural areas or overseas.

Urban Sprawl

Even if urban growth is explained by older theories of natural processes or by growth machine theories, the fact remains: cities have grown rapidly throughout the twentieth century.Growth has been poorly managed in some cases, as evidenced by urban sprawl. Because of urban sprawl's segregated land use, people live, work, shop, and relax at different points, which makes walking, public transportation, and bicycling very difficult.Residents are therefore forced to drive an automobile.As a result of sprawl, there tends to be low population density. It includes: single family homes on large lots rather than apartment buildings, one-story or low-rise buildings rather than high-rises, large lawns and surface parking lots, and so on. Urban sprawl opponents assert that it creates a hostile urban environment and encroaches on rural land, possibly posing a threat to farmers or rural residents.

Urban Decay

Consumer preferences seem to drive urban sprawl, with people preferring low-density, quieter, more private neighborhoods because they perceive them to be safer and more relaxed than urban areas.Such preferences echoes a common criticism of urban life, which focuses on urban decay.Urban decay is the result of excessive densities and crowding in cities, which drive residents out, creating urban sprawl.


There is an alternative theory that suggests that density does not cause crime, or crime to cause people to leave the city; when people leave, the city's neighborhoods are abandoned and neglected, leading to crime and decay.This theory, referred to as "broken windows," proposes that small indications of neglect, such as broken windows and untidy lawns, contribute to an area's perceived decay.By anticipating decay, people also fail to maintain their own properties.


In response to the urban decay and sprawl of cities, urban renewal programs have been launched.In New Urbanism and smart growth, two types of urban renewal are being pursued to make cities more pleasant and liveable. Urban sprawl's segregated land use places people's homes, workplaces, shops, and leisurely activities far apart, which prevents them from walking, taking public transit, or riding a bicycle.Because of this, residents must use an automobile.As a result of sprawl, there tends to be low population density. It includes: single family homes on large lots rather than apartment buildings, one-story or low-rise buildings rather than high-rises, large lawns and surface parking lots, and so on. Urban sprawl opponents assert that it creates a hostile urban environment and encroaches on rural land, possibly posing a threat to farmers or rural residents.There are also many negative environmental and public health effects associated with urban sprawl, many of which are caused by automobile dependence: higher vehicle ownership costs, air pollution and reliance on fossil fuels, traffic accidents, delays in emergency medical services response times, and reductions in land and water quantity.