The Tigris & Ephrates (rivers) made the soil in mesopotamia rich & fertile. People that settled in mesopotamia used the soil to grow crops. They grew so much that they had a food surplus. The extra food allowed mesopotamia to have a bigger population. That is mesopotamia got to cities.
The sumerians in mesopotamia practiced polytheism (the worship of many gods). They where so orginized that they made a name for there temples; the temples names where ziggurats. the temples shape was a pyramid. They where so orginized that they had different rooms for each god.
The gov. was so orginized that they made the first recorded laws (hammurabi's code). The gov. also made canals to keep crops, humans, animals, and houses. The goverment helped the people be safe by irragation.