Why did civilizations start by rivers?

Rivers were crucial to the survival of early civilizations because they were responsible for providing a source of water, irrigation for good farmland and a way for people to trade with other people through water transportation. Many of the earliest civilizations thrived due to the availability of rivers such as Mesopotamian cultures with the Euphrates River and Tigris River, Egyptians with the Nil

Explanation:

using the bering strait was the best transportation system.