Audience: Students; Grades: 4-12; Subject Areas: History. (2003) Describes how the Tigris and Euphrates Rivers affected the early Mesopotamian civilization. Looks at the food, tools, and pottery of the early Mesopotamians as well as their innovations, which include irrigation, the wheel, clay pottery, clay bricks, and cuneiform writing. Explores the social structure of Mesopotamian society. Describes Sumerian culture and religious beliefs. Discusses the rise of Agadian King Sargon, who unified all of Mesopotamia, and the Sumerian King Ur-Nammu, who wrote the first code of laws.