Wikijunior:Introduction to History/Industrialisation
People flocked to cities to work in factories. While in earlier ages most people lived in the country, working on farms, today most people live in cities. At first, industrial cities were crowded, dirty, and disease ridden. In London, the skies were black with soot, and after working for twelve hours in a factory, the people would crowded into bars, called gin mills, to spend their hard earned coins and drink themselves into a stupor -- it was the only way they could sleep amid the stench and the crowds. Children had to work, too, and the gin mills had steps that small children could climb to exchange their hard earned coins for a shot of gin. If the cities were such horrible places, why did people flock to them in such numbers? Because it beat farming.
Then several things began to happen. The number of people that modern farms could feed was much greater than the number that the old style of farming could provide for. Also, as the science of medicine began to cure diseases, people began to live longer, and fewer babies died. The population began to explode.