The City is a relatively recent form of social organization.
A "city" refers to a place of relatively dense settlement -- dense enough so that city residents can not grow their own food. A city population, therefore, is always dependent upon its "hinterlands" to provide it with food. Not until agriculture developed could hinterlands provide food for their own populations and enough of a surplus to feed a city population. And in agricultural societies the surplus was so small that only a tiny proportion of an entire population could live in cities. Up until very recently -- about 200 years ago -- that proportion was limited to about 5% of an entire population. So cities existed, but there was no urbanization.
Urbanization refers to a process in which an increasing proportion of an entire population lives in cities and the suburbs of cities. Historically, it has been closely connected with industrialization. When more and more inanimate sources of energy were used to enhance human productivity (industrialization), surpluses increased in both agriculture and industry. Larger and larger proportions of a population could live in cities. Economic forces were such that cities became the ideal places to locate factories and their workers.
In the United States, about 5% of the population lived in cities in 1800, but about 50% of the population lived in cities by 1920. Throughout the 19th century, the US was urbanizing. The same was true for most European societies during the 19th century.
Today about 80% of the US population lives in cities and suburbs. Since no more than 100% of a population can possibly be urban, urbanization as a process is coming to an end.
How many major US cities can you locate in this satellite photo?
Notice that at mid-century only 17.8% of the population
of Third World societies lived in cities, but in the fifty years since
1950 that percent has increased to over 40%. By the
year 2030, almost 60% of Third World populations will live in cities.
In just a few years the World will become predominately
urban -- about 80-85 years after that happened in the United States.
There is a very big question related to Third World urbanization:
Will it prove beneficial for people's lives? Much of Third
World urbanization is the result of overpopulation in the countryside.
In villages babies have been living and not dying. A husband and
wife who farm 15 acres might have three sons and three daughters.
All now live and grow up. But there is not land enough for them to
have the farms they need to marry and raise a family. This
lack of land for burgeoning rural populations forced them to leave the
village and migrate to cities. They find a place to live in the favela's
and shantytowns -- such as the one pictured below -- but often
times they don't find productive employment.
Third World urbanization will be a beneficial social trend
only if enough good jobs can be found for the rapidly growing population
of Third World cities.