What are the rivers of Mesopotamia?

The name Mesopotamia comes from the Greek for "land between rivers." And the rivers in question were the Tigris and the Euphrates. They contributed greatly to the development of ancient civilizations in the region as regular river floods made for fertile soil in which to grow crops; the Tigris and the Euphrates were also used to supply fresh water for crop irrigation. The regular food supply to which this led ensured a rapid growth in population, turning Mesopotamia—part of the appropriately-named Fertile Crescent—into the cradle of Western civilization.
The two great rivers were also used extensively for navigation, which enabled the development of trade and commerce between Mesopotamian and other cultures. Thanks to these vast waterways the Sumerians, Assyrians, Akkadians, and Babylonians were able to travel widely, interacting with other early civilizations such as the Harappans in what is now Northern India. In relation to trade, the Mesopotamian civilizations exchanged textiles, leather goods, and jewelry for Harappan semi-precious stones, copper, pearls, and ivory.