The early civilizations of Mesopotamia, Egypt, India, China, and the Americas that thrived near the year 3500 BCE, were known as the river valley civilizations. These civilizations were mainly patriarchal societies, due to the rise of agriculture; therefore, their political positions were held by upper-class males, and their domestic responsibilities were held by women. Due to trade, their cultures, religions, and technology were fairly similar. Mesopotamia and Egypt both contributed to modern technology with the Egyptian pyramids, and Mesopotamian arithmetic, but they differ in their location which lead them to have a different views of the afterlife.