John Locke is the answer! hope this helps
The communist faction had claimed the entire country. With the "true" government exiled to Taiwan. Some years later the United States helped the "True" government to take back its' country.
The mason Dixon line was a border dispute in 1763 to 1767 with Charles Mason and Jeremiah Dixon, and was a resolution involving Maryland,Pennsylvania, and Delaware, so the states below the border are non demarcation states