Rural areas are defined as "all territory, population, and housing units located outside of urbanized areas and urban clusters (cities) and their surrounding suburbs1.
Rural in the United State
According to the 2000 Census, 2,052 rural counties account for 97% of the land area in the United States.2 The 2000 Census puts the rural population of the United States at 59 million.2 Only one percent of the rural population are farmers.3 The average size of the nation's 2.1 million farms is 441 acres.3 Rural areas are often admired for their strong American and family values, and they usually vote Republican.
 U.S. Census Bureau Glossary
 Research and Training Center on Disability in Rural Communities, The University of Montana Rural Institute
 Amber Waves
Rurals are the primary source for inexpensive and safe food, affordable energy, clean drinking water, and accessible outdoor recreation. However, the safety and low cost of the food that U.S. farmers provide is often taken for granted. Besides farming rural communities also provide the home of many of the country’s energy production resources, such as coal mining, renewable fuels like ethanol and biodiesel, wind and solar energy, and gas and oil production. 
Urbanization is defined as the increase of the percentage of people who live in Urban Areas. This may occur due to people moving from Rural Areas to Urban areas, or Rural Areas becoming Urban Areas in their own right (such as a growth in population). For example, artificially new cities such as Brazillia, Brazil turn a rural area into an urban area. Rapid urbanization may result in Rural Decay where rural areas fall into disarray due to a decreased or non-existent population.
Political Leanings of Rural Areas
Rural areas tend to be more conservative than cities in many countries. In the United States, heavily rural states such as Montanta and Kansas on the whole vote Republican while more urban states such as New York and California leant Democrat. Other countries follow the same trend such as in Britain and Japan where cities traditionally vote for the Labour Party and Democratic Party of Japan respectively (left-wing) and rural areas vote for the Conservative Party and Liberal Democratic Party respectively.
For all the bad tidings, there is one important development that could bode well for Democrats in some Southern states. While they may never get back the rural areas that once served as their bulwark, Southern Democrats are now competitive in some fast-growing suburbs in states that have a significant number of transplants. There was a reason why Obama won Virginia and North Carolina in 2008 -- both are filled with newcomers who are open to supporting either party.
Jonathan Martin