The congestion in the 19th century industrial London had led many wealthy residents of London to build homes in the countryside. Architect Ebenezer Howard developed the principle of ‘Garden City’, a pleasant place, full of plants and trees, where people could both live and work. Between the two world wars, the British State built a million houses, single family cottages for working classes. The city extended now beyond the range, where people could walk to work. The development of suburbs made new forms of mass transport absolutely necessary.To persuade people to leave the city and live in garden suburbs, some new means of travelling to the city for work was essential. The London underground railway solved the housing crisis by carrying large masses of people to and from the city.