It was the first to practice intensive year-round agriculture ; it gave the rest of the world the first writing system , invented the potter 's wheel and then the vehicular - and mill wheel , created the first centralized governments , law codes and empires , as well as introducing social stratification , slavery and organized warfare , and it laid the foundation for the fields of astronomy and mathematics . It was the first to practice intensive year-round agriculture , it gave the rest of the world the first writing system , invented the potter 's wheel and then the vehicular - and mill wheel , created the first centralized governments , law codes and empires , as well as introducing social stratification , slavery and organized warfare , and it laid the foundation for the fields of astronomy and mathematics .