Probably nuclear because as seen in the bombing of Hiroshima & Nagasaki, both cities were leveled with ruins of building left.
The U.S. Constitution establishes six-year terms for members of the Senate in order to: A. make senators more responsive to public opinion. B. allow senators to focus on long-term national issues.
They started domesticating wheat. This wasn't their main feat however since they also started herding sheep and domesticating goats. These two enabled them to stop moving around like nomads and make a real civilization in the area which resulted in what is now known as history.
