The growth of trade, construction and writing in Mesopotamia

Mesopotamian civilisations like the Sumerians were able to trade their extra food with people who lived far away. Archaeologists think that as these civilisations traded more they needed a way of recording what was being traded. They began to write down and count what they were giving and receiving in a special writing called cuneiform. Because their farming was productive, they could stay in one place, and so they built cities with large stone buildings. Some of the biggest of these stone buildings were called ziggurats, which were large, stepped religious buildings.