People agree to social contracts because they establish governments which in turn establish a sense of order and security. It establishes a set of rules which makes people more comfortable when they have some to follow.
The answer would be the geography of the country. Its mountain terrain and bodies of water created a boundary to each city-state. Each city-state created their own society. For example, Sparta had created a military society while Athens is the center of many intelligent people. Each city-state also has their worshipped specific gods, Aside from Zeus, Poseidon, and Hades.
The answer is A they worked long hours and had low pay.
Because of British seizure of American ships and because of impressment of American seamen. :) I hope this helps!