There are various community that settled in Mesopotamian civilization, which have many different ethnics such as
Sumerian, there were dam buildings in order to solve a drought problem, inventing cuneiform, and developing the trade system.
Akkadian, there were setting up the capital, and spreading cultures of Sumerian, but couldn’t live in the long term due to losing from Barbarian invading.
Babylonian, there was the codification, which is called the code of Hammurabi.
Assyrian, there were reuniting Mesopotamia and using an iron instead of using wooden and using an iron as weapons. Those things had changed lifestyle of people.