“In what ways were the civilizations of Mesopotamia (Sumer and successor states) and North Africa (Egypt) alike? In what ways were they different? What accounts for the similarities and differences?
I believe that the SIMILARITIES between Egypt and the civilizations of Mesopotamia are:
Both civilizations born and thrive in the desert
Both used the rivers floods to supply their cities and allow agriculture.
Both civilizations were polytheists
In the case of DIFFERENCES, we can list the following:
While Egypt was a unified empire, in the civilizations of Mesopotamia we had a group of cities, independent and with their own government system, very similar to what happened in Greece.
When it comes rulers, in Egypt the Pharaoh was considered a god and was worshiped alike, while in Mesopotamia, despite the religious feature of their kings, they were not worshiped.
Despite their religious system was similar (both systems were polytheists), Egypt we had anthropomorphic deities while in Mesopotamia gods were humans.