The Sumerians may well have been the first civilization based around cities in Mesopotamia, which makes it likely that they were the first such civilization anywhere. In fact, the Sumerians are credited with many “firsts”: the wheel, cities, writing…. This article from the History Channel details 9 things about the Sumerians that you may not know.
link to 9 Things You May Not Know About the Ancient Sumerians
Humanities Scholars 