record keeping in ancient cities

The world's first ancient cities of the first ancient civilizations rose around major rivers. The Egyptians settled around the Nile, the Mesopotamians between the Tigris and Euphrates, and the Chinese around the Huang He or Yellow River. We know that these were the homes to the first large cities because there archaeological ruins and there are written records.

When ancient man first decided to settle in cities they did it for many reasons. Protection, to sell more of their product and to be closer to markets are just a few reasons why people came together. And as it is with when any large group of people get together there needs to be a leader. In those days the main duty of the leader wasn't to decide on if a universal healthcare system was necessary or not but instead to serve as a link to the gods. And so the leaders were holy figure heads who were not to be second guessed. This was just one duty of the leader, the other duty was to protect his citizens. Such a job required soldiers who needed payment and with that arose the first system of record keeping.
The Chinese managed to develop a form of shorthand that used pictures as symbols for words much like Egyptian hieroglyphics and then later the Phoenicians worked to create a written alphabet and pave the way for written language. These forms of record keeping allowed them to keep track of how many crops a farmer had grown, how many soldiers had died in battle, how one should worship the gods and most importantly how much payment each man owed the government.
It is through these records that we are able to see how large each city was and how rich its inhabitants. Through agricultural records we are able to see what years yielded bountiful harvests and which years had withering droughts. Basically it is through deciphering the records of ancient civilizations that we are able to learn more than just the physical dimensions of a city.