Defining "civilization" can be tricky. It's one of those "I know it when I see it" things. But we can also get boxed in if we focus too intently on defining civilizations based on certain characteristics. I challenge students to come up with their own definitions of civilization and broaden what might be considered civilization. Could the societies of our Ice Age ancestors not be considered civilization? What of the hunter gatherers who existed both then and now? And what about societies that do not follow "conventional" ways of organizing? Perhaps they shift their location and social structure seasonally. Must civilization be consistent?
At any rate, some of the first major civilizations formed across the world at roughly the same time and became increasingly complex. Below are resources for some of these societies in Mesopotamia, Africa, Asia and the Americas.
What Makes a Civilization intro activity with case studies and creation myths
Viewing Guide for PBS First Civilizations: Religion (Egypt)