Depending on the time, it could be the Phoenicians ( I think this is the best answer; this is what they're known for best) or later in time, the Romans (but they had colonies also elsewhere).
Divorce is mentioned in the Bible, the main source of authority and guidance for Christians. Jesus's teaching on divorce is that it would lead to adultery, which is forbidden in the Ten Commandments, but he did allow for divorce in the case of a partner's infidelity.
They were not allowed to leave and so they had to stay
The Monroe Doctrine and the Roosevelt Corollary made it possible for the United States to go to Latin America and try to make them a part of the United States. The Roosevelt Corollary made it possible for the Monroe Doctrine to be enforced.
