Industrialization caused large amounts of people to move to the cities of England during the 18th and 19th centuries for two fundamental reasons. Both reasons were as a result of the economic principle of supply and demand. First, the mechanization of farming tools led to higher individual crop yields for each farm. This meant that each farmer could produce more than they had in previous generations. The implication of this is that not as many farm workers were needed to produce even more crops than in the past. This led to a drastic decrease in the demand for agrarian workers.
A second reason that urbanization occurred with industrialism is because the profitability of manufacturing led to a high demand of unskilled workers. The labor pool would naturally come from the now displaced farm workers mentioned earlier. Factories were placed in the urban areas because of the better infrastructure, transportation networks, and technologies found in the cities.