Economic factors have to do with how Rome made money. Think of shipping on the Tiber and proximity to the seacoast. Think about the farmland surrounding Rome.
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How is this answer then?
Economic: Economially, the Tiber river allowed for trade to happen throughout Italy and along the Mediterranean Sea. Also, the great amount of fertile land allowed for the growth of crops, the main part of the Roman economy.
Social: When the Estrucans began their rule, they did not destroy the native Roman practices, leading to a mix of native Roman and Estrucan elements in Roman society.
Historical: According to legend, Rome was founded by Romulus and Remus, forming a small village of huts on the tops of the hills. Early Rome was said to be controlled by seven kings, of which two of the last three were Estrucans, and whether this list of kings is true or not, Rome fell to Estrucan power. Estrucans began to control Rome for about one hundred years, and during this time Rome began to emerge as a city. The Estruscans began an outstanding building program, with the construction of the roadbed of the chief street along with the construction of temples, markets, shops, streets and houses.
Geographic: Rome is a city in Italy, a peninsula about 750 miles north to south divided by the Apennine mountains from east to west, on the Latium plain. Many Seas encompass the area, including the Mediterranean, Tyrrhenian, Ionian and Adriatic Seas. Rome itself was located eighteen miles inland on the Tiber River, giving Rome access to the sea and yet protection from pirates. Their was a good amount of land for agriculture, and seven hills for protection. The Tiber River could be readily forded, letting Rome become a natural crossing point for north-south traffic in Italy. Other than being centralized, Rome also was right between the eastern and western regions lead to an involvement in Mediterranean affrairs.