I am absolutely sure that the statement represented above : Deep within the jungles of Mexico and Guatemala lie most of the Mayan ruine is TRUE. I think so because Mayans are actually originated in the areas which are stated in the question. So I am sure it will help you!
Cheers.
Answer for the second
'Released from foreign war, we would probably be plunged into all the misery of anarchy and intestine war. Can we suppose that the people of the south, would submit to having the seat of Empire at Philadelphia, or New England; or that the people oppressed by a change of government, contrasting their misery with their former happy state, would not invite Britain to reassume the sovereignty.” — James Chalmers, Plain Truth, 1776
If the one above is the argument, you might consider that the colonists did obtain independence from England. That by itself was something that Chalmers always thought to be impossible without serious repercussions. He used to say that in the case of achieving freedom, America would just end up being attacked and maybe even colonized by some other country. What happened, thought, was that after the revolution, other countries gained respect for America as an opponent and the country was eventually left to be.
"Agriculture, was followed by job specialization, then by social stratification, and finally by chiefdoms" would be correct, since agriculture allowed people to go off and do other jobs since there was a surplus of food.