One reason for the success of the cities in the hanseatic league and the italian city-states were that both were accessible by water.
Henry W. Grady believed the South's dependency on cotton farming was a bad thing because it kept the South dependent on the North for crops and other supplies/materials.
The first Greek kingdoms were established by the Athenians. These were people who were an advanced race that developed different forms of traditions and cultures which spread throughout Greece.
The collapse of the Mycenaean civilization was that people have forgotten their written language. History accounts on this have not been concluded but this demise was probably the biggest reason why the civilization had ceased to exist.
When saddles were created, it was made possible for camel riders who had caravans to go for much longer and further without resting both them and the camels. This made it possible to reach places quickly and trade more efficiently, which is why the economy developed massively.