What factors led to the development of early civilizations mesoptamia?

several factors played a part in the development of early civilizations in Mesopotamia, but the most important factor was its location. Mesopotamia is situated between two very fertile rivers, which allowed agriculture to expand for the first time in human history, hope it helps :)

This was the first time farmers had an excess of what they needed.The tigrus-euphrates river system where mesopotamia started The flooding deposited valuable silt onto the land and enabled crops to be grown and harvested in surplus.        WWW.RECOURCES.COM . (where half came from).