Answer:
Nile river = Egyptian Kingdoms (Upper and Lower combined)
Tigris and Euphrates = Sumerian Empire (Mesopotamia)
Yellow River = Chinese Empires (not sure which ones)
Indus and Ganges = Indian Kingdoms (hundreds and hundreds)
Mississippi = Native American Tribes (not sure which ones)
Yukon= Eskimos?
Rio Grande, Amazon Rivers = South American Native Tribes
Explanation:
Look for more information online (NOT WIKIPEDIA!!!) or in your textbook! :)