How do people find food in complex civilization

People started out as hunter/gatherers meaning they had to constantly migrate to find food. What allowed civilization to become complex was the easy access and amiability of food. Once one farmer could feed hundreds if not thousands of people that allowed others to devote time to specializing task such as blacksmiths and creating a writing script thus keeping records. The successful farmer more than likely needed help from a family member or neighbor to sell his crops thus eventually a market system was created. The wheat farmer,the sheep herder,the rice farmer and orchard farmer all brought there goods to a central location..ie: an ancient piggly wiggly

that was the type of government the spanish colonists were used to.