Overpopulation occurred during the First Industrial Revolution, but with the improvement of working conditions in the late 1800s, shortening working hours, the situation improved somewhat and the middle class emerged. This was achieved by many strikes by trade unions and workers. The middle class were skilled workers, officers, accountants and others. Because of better conditions and salary increases, they could meet basic living needs, and save money for other things. So they slowly began to move out of urban areas near unhygienic city neighborhoods. Unlike them, unskilled workers remained in unhygienic urban neighborhoods and lived in city tenements.
