Tell us what 'Zhong Guo' meant in 1849 and 1749 etc.
Zhongguo wasn't used in its modern sense in 1849 and 1949. That's the point. It wasn't until the early 20th century, when Zhongguo became a term used to describe the Chinese nation-state in the Western sense. This was also when the term Jhonghua Minguo was coined. Thank you for revealing that you have no grasp of the historic development of the Chinese language.