Compare Mesopotamian civilization with Egyptian civilization.
Mesopotamia and Egypt were both ruled by strong leader that the people thought were gods or descendents from God. In Egypt they were called pharaohs and in Mesopotamia they were simply kings. Both civilizations went through some kind of political consolidation at some point in their histories. They were also both religious and merged their religions with their politics. Both civilizations constructed huge scale building projects to include temples and irrigation projects. Finally, they were also both very much isolationalists. They traded a bit with others but mostly stuck to themselves.
Why were there several different regional societies following each other in Mesopotamia, but only on native society in Egypt?
Mesopotamia struggled a bit more than Egypt in having a dedicated food source and other commodities. Because of this, they were more divided and had city-states with each being ruled by a different king.
Egypt on the other hand was more unified socially and was ruled by one divine leader, the pharaoh. Different city-states being ruled by different leaders meant there were different regional differences in Mesopotamia especially compared to Egypt where one ruler meant one set of rules for the entire empire.
Why is there a greater western legacy from Egypt than from Mesopotamia?
There is more of a western legacy from Egypt than from Mesopotamia because Egypt left behind more cultural artifacts from day to day life. Egypt was able to focus on art and literature more than the Mesopotamians who mostly seemed to focus on war. Since they were able to do this, there was a lot more of their culture and legacy that was left behind to be passed down and "discovered" later on.
How was the Hebrew religion different from the religions of the other...