Tiber River. The most important river in central Italy. It runs some 400 kilometers through a long valley running from Tuscany through Umbria, Latium, past Rome, to the Tyrannize Sea at Ostia (literally, the “mouths” of the river). The river had a positive as well as negative impact on the development of Rome.
The Mediterranean Sea was important to the Roman Empire in that it was a vital trade link with other parts of the Empire, especially the Middle East and North Africa. ... The Romans referred to it as "their sea" and would not allow competing empires to flourish on it, such as the Greeks and Egyptians.
A key factor that pushed Mexicans to emigrate was not being able to support themselves at home, politics also affected them.
Technology is probably the answer that you need. Other answers such as internet, cell phones, and airplanes are suitable answers as well.
