Suburbanisation is when a city expands outwards and starts to engulf some of the villages/hamlets residing around the rural-urban fringe.

The population of Manchester grew rapidly at the start of the Industrial Revolution, climbing continuously from 95,000 in 1801 to a peak of 750,000 in 1931. The population has declined since then, with a recorded 392,819 in the 2001 census, a 9.2% drop since 1991.

Inner London also saw continuous growth in the 19th and early 20th centuries, with the population rising from 879,491 in 1801 to a peak of 4,997,741 in 1921. Seven decades of declining population was halted in 1991, with an increase of 200,000 over 1981 and a further increase in 2001 to a recorded population of 2,765,975.

The population growth of Outer London is far more marked than Inner London, rising from 131,666 in 1801 to a peak of 4,483,595 in 1961, much later than the Inner London population peak, probably caused by suburbanisation as people moved out of the depressed and run-down inner city. After falling for thirty years to 4,182,979 in 1981, the population of outer London has risen since and was recorded as 4,406,061 in 2001, only a few thousand off the all time peak.

Urbanisation happended in the 1900s onwards in MEDCs like the USA and UK. It started with the Industrial Revolution, where factories attracted a lot of workers to move nearby. These workers required houses and services (schoold, doctors, shops) and so urban settlements began to grow. As people became wealthier adn more mobile they started to move to the suburbs (suburbanisation) and eventually to the rural urban fringe (counter urbanisation).

However, urbanisation is still occurring in LEDCs like Brazil and India. This is due to massive rural to urban migration, where people move to the cities to escape the serious rural poverty that exists in countryside areas. This has lead to a huge increase in urban populations in LEDCs and has lead to the development of shanty towns in such areas.

Because many wealthy investors thought it had huge economic potential as a means of speeding up transit of goods & people between manufacturing centres, markets, & ports. Early C19th England/ Britain was full of wealthy entrepreneurs (many of whom had made huge profits from the "Triangular Trade" - ie Slave Trade & associated manufacturing & export/ import trades) who were constantly looking for new investment opportunities. Canals & roads had already done much to facilitate business/ trade; railways looked like the "next big thing" where transport/ communications were concerned. They were not wrong!

The first public line was the Stockton - Darlington railway, opened in 1825: engineered by George Stephenson to demonstrate the viability/ utility of the emerging technologies of steam rotary motion (developed by James Watt, 1781) & iron tracks. It provided a great investment opportunity for venture capitalists, plus a huge stimulus to coal, iron, & engineering industries.

In 1826, George & Robert Stephenson undertook design & construction of the Liverpool - Manchester line (completed 1830), a phenomenal engineering feat that included the Olive Mount Cutting, Sankey Viaduct, & the crossing of the Chat Moss bog. This linked the port of Liverpool (cotton, tobacco, sugar etc from the Americas) to Manchester, centre of the cotton manufacturing industry.

The long-term economic impact of the railways on Britain is contested: canals continued to handle most internal bulk good carriage, but there's little doubt that the massive railway construction of the 1830s onwards was a great economic stimulus, arguably saving British venture capitalism from crisis in the mid C19th. Without doubt, railways "shrank the world", & greatly enhanced movements of people around Britain. The coming of the railways led to standardised time throughout the UK, and also made daily newspapers & a national football league viable. Ultimately, they also made suburbanisation & commuting to work increasingly attractive & feasible.

Suburban communities are closely-knit environments in which the inhabitants usually have something in common, such as yearly income, work places (such as a university, or corporation), or some sort of shared value. However, while the houses are in most cases placed very close together- which may be seen as a negative aspect in itself- there is a certain tendency towards isolation of the family units. Suburbs can be places of extreme social pressure to look or act in a certain way, because people that live in a given suburb share similar socio-economic backgrounds, there is often an unspoken ideal, or standard which people are expected to adhere to. Other negative aspects may include a lack of privacy, gossip, and unpleasant competitiveness. Additionally, depending on the area of the country the suburb is, the houses themselves may be poor in quality, or not likely to hold up in natural catastrophes because they are built quickly and on strict deadlines. These things will vary from state to state, and the homes in wealthier suburbs may be spaced farther apart, leaving less of an impression of living in a concrete jungle, or ticky-tacky boxes. Contrary to popular opinion, suburbs are not necessarily safer than inner-city neighborhoods, while you are less likely to be the victim of a violent crime such as a mugging while walking through a suburb, statistics show that drug abuse, domestic disputes, and white-collar crimes like embezzlement and fraud are just as likely to take place in suburbs as they are in other more diverse communities.