Sumerian civilization emerged in 3,500 BC in the southern region of Mesopotamia (corresponding to modern-day Iraq and Kuwait), relying on agriculture as the primary source of livelihood, creating the irrigation systems by constructing dikes and canals to control flooding, building large structures from sun-dried bricks made of clay, inventing the wheel, sail, and plow, improving trade and farming, forging bronze from copper and tin around 3,000 BC, allowing for more robust tools and weapons, and developing the first formal writing system called cuneiform.