Today the continent that Mesopotamia was in is in Asia. The country is Iraq. Also, the two main rivers that helped the civilization are the Tigris and the Euphrates.
The people had to move to the foothills of Zagros. But a problem arose. People were suffering from food shortages because people didn't have enough land to grow food for the people that were moving to the foothills. Because of the food shortages people started moving to the plains of Sumer.
There was another problem. The rivers started to flood and the farmers' crops would get washed away if they already planted them. Luckily the farmers created irrigation systems. They also built levees beside the rivers to help prevent the floods.
The irrigation canals had to be cleaned out because they were clogged with silt. The farmers had to work together to make this happen. Because people worked so well together cities formed.
When the cities grew larger the people started fighting over their water and that led to constructing walls and moats around the cities.
In conclusion, the people had to go through a lot. For example, the people had to move from Zagros to the plains of Sumer because of food shortages. In Sumer the rivers flooded and the people had to build irrigation systems and levees. Then the irrigation canals were clogged with silt so farmers had to clean it out. People started to fight over water when the cities got so big and so the people built moats and walls to protect their city, creating city-states.