Answer:
They had a surplus of food, they divided labor and built cities.
After the development of the irrigation systems, they could grow more wheat and that meant more food for the growth of the population.
They divided labor between themselves. Who will harvest crops, who will tend to the irrigation systems, who will tend to fields. They had a lot of other workers such as carpenters or soldiers and that means that they knew how to divide labor between the population.
They started to build cities so they could work together, trade, store food, and the cities grew as more and more people came to live there.
I believe it was the civil rights act of 1964.
I would argue that one cannot judge the fairness of any particular distribution without knowing something about the rules of the game that gave rise to it. Imagine a society in which incomes were as
It was president Bill Clinton