Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia, modern-day southern Iraq, during the Chalcolithic and Early Bronze ages, and one of the first civilizations in the world along with Ancient Egypt and the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers were able to grow an abundance of grain and other crops, the surplus of which enabled them to settle in one place. Prehistoric proto-writing dates back before 3000 BC. The earliest texts, from c. 3300 BC, come from the cities of Uruk and Jemdet Nasr; early cuneiform script emerged around 3000 BC.
Olmecs
The Olmec may have been the first civilization in the Western Hemisphere to develop a writing system. Symbols found in 2002 and 2006 date from 650 BCE and 900 BCE respectively, preceding the oldest Zapotec writing found so far, which dates from about 500 BCE.