The document provides an overview of several ancient civilizations that arose along major river valleys between approximately 3500 BC and 640 AD. It discusses the Mesopotamian civilizations of Sumer, Akkadia, Babylonia, and Assyria located along the Tigris and Euphrates Rivers. It also summarizes the Egyptian civilization in the Nile River valley, the Indus River valley civilization in India, and the civilizations that arose in Central and South America including the Incas, Aztecs, and Mayans. Additionally, it briefly outlines the dynastic history of ancient China and the Phoenician city-states.