Final answer:
The emergence of urban societies in Mesopotamia, particularly around 3100 BCE in the Sumerian city of Uruk, is considered the first major event in the history of civilization.
Step-by-step explanation:
The first major event in the history of civilization was the emergence of urban societies in Mesopotamia. Around 3100 BCE, Mesopotamia, also known as the Cradle of Civilization, saw the rise of some of the first true cities in the world, such as Uruk in the land of Sumer.
This marked a pivotal moment in human history, characterized by the development of agriculture, the innovation of new technologies like the wheel and cuneiform writing, and the establishment of complex social structures and political networks.
Mesopotamian civilization grew over thousands of years, culminating in a sophisticated society around 3000 BCE where intensive irrigation agriculture underpinned the urban growth. The Sumerians were responsible for many significant technological advances, which further facilitated the rise of a complex culture throughout Mesopotamia. The discovery of Mesopotamia and its history provides invaluable insight into the development of human civilization.