You could do it but not with a civil war pod, go farther back, the American revolution. Georgia doesn't join and remains a British colony until say maybe during an alt 1812 conflict its invaded but not annexed and the US props up a Republic of Georgia under the thumb of the US.
They don't annex it because of a treaty with Spain regarding Florida and the country serves as a buffer between the two.
They don't annex it because of a treaty with Spain regarding Florida and the country serves as a buffer between the two.