The three fifths compromise was an agreement on how to count slaves for the purposes of taxation and Congressional representation. A slave would count as 3/5 of a person.
Since the main economic activities revolve around the NASA's space center because of the quantity of people it attracts and works there, once the facilities are closed you can predict their average household income shall decrease because there will not be as many people around anymore. This has happened in other cases with petroleum companies, many towns have formed around their facilities and once they move the towns have to face a big income decrease.
12,000+ ago (it may or may not be right)
The last answer: they demanded payment of bonuses promised to veterans
