What do textbooks normally do to the river valley civilizations?

I believe the answer is: River valley civilizations are oftentimes split up into separate civilizations.

Many textbooks described that river valley civilizations eventually split into several regions which later on become Egypt, Mesopotamia, and China. Even though this is entirely possible, there is no solid historical proof that could be used to defend this claim.

two months after his defeat of napoleon bonaparte's colonial forces, jean-jacques dessalines proclaims the independence of saint-domingue, renaming it haiti after its original arawak name. in 1791, a slave revolt erupted on the french colony, and toussaint-louverture, a former slave, took control of the rebels.

a

explanation: