Why do you think so many of our major cities in the world are located near bodies of water

Factories located near bodies of water because it allowed them to be powered by the water. Factory work was very important for people, as many of them moved near the factories. As more and more people came, the cities urbanized. 

Farming in early communities led to more reliable and abundant food supplies, that is, farming began a process of intensification, which, in turn, increased the population and led to specialization of labor and, therefore, new social orders. An explanation for this is that societies needed to adopt new approaches on how they organized their lives: a leader was needed to facilitate cooperation between these many different groups and to manage huge amounts of people working together for large-scale construction projects, such as the construction of a monument. This paved the way for the change in social roles to occur.