History of the world
Whether in prehistoric or historic times, people always needed to be near reliable sources of potable water. Settlements developed on river banks as early as 3000 BCE in Mesopotamia, on the banks of Egypt's Nile River, in the Indus River valley, and along China's rivers. As farming developed, grain agriculture became more sophisticated and prompted a division of labour to store food between growing seasons. Labour divisions led to the rise of a leisured upper class and the development of cities, which provided the foundation for civilization. The growing complexity of human societies necessitated systems of accounting and writing.
Maya civilization
The Maya developed their first civilization in the Preclassic period. Scholars continue to discuss when this era of Maya civilization began. Maya occupation at Cuello (modern-day Belize) has been carbon dated to around 2600 BC. Settlements were established around 1800 BC in the Soconusco region of the Pacific coast, and the Maya were already cultivating the staple crops of maize, beans, squash, and chili pepper. This period was characterized by sedentary communities and the introduction of pottery and fired clay figurines.