The late author, William W. Johnstone, wrote an entire series of books about a second civil war between the states, culminating in the southern states defeating the northern states and establishing a new country, the SUSA (Southern United States of America), based on the principles of the original founders of the United States. Through the books, the SUSA thrived and prospered, while the old USA withered and became more and more subject to the rule of corrupt politicians to whom individual freedoms were anathema.
The series is known as the Ashes series. I recommend them, if you can find them.
If anyone finds Johnstone's writing to be enjoyable, be aware that he died in 2004. His estate and his publishers concealed the fact of his death for three years, and even now they continue to publish new titles under his name (sometimes attributed to William W. Johnstone "with" J.A. Johnstone. Wikipedia says J.A. Johnstone is his niece; I think it's a pseudonym for one or more contract writers who churn out books so the publisher can capitalize on the Johnstone name. According to Wikipedia, 330 books have been attributed to him since his death.
So ... if you can find the books in the Ashes series, by all means read them. For any other Johnstone books, skip any that were copyrighted after 2004. They're trash.
(Disclaimer: I once wrote to the real William Johnstone with some thoughts about another of his series, and he was good enough to reply. I corresponded with him irregularly for awhile before his death. That allows me to feel suitably outraged that the publisher is profiteering off Bill's name.)
There are 36 books in the Ashes series. The last was published in January of 2004 and may or may not have been written by Johnstone himself.