Answer:
They built walls around their cities for protection
Explanation:
Sargon the Great
Around 2,300 BC, the independent city-states of Sumer were conquered by a man called Sargon the Great of Akkad, who had once ruled the city-state of Kish. Sargon was an Akkadian, a Semitic group of desert nomads who eventually settled in Mesopotamia just north of Sumer.
A Simple Yet Powerful Economy
Ancient Rome was an agrarian and slave based economy whose main concern was feeding the vast number of citizens and legionaries who populated the Mediterranean region. Agriculture and trade dominated Roman economic fortunes, only supplemented by small scale industrial production.