A useful tool for writers is Google ngram, that tracks the use of words or phrases in books over time:
https://books.google.com/ngrams
You can also search for words and phrases in old newspapers, like at the LoC:
http://chroniclingamerica.loc.gov/
These tools can give you a good idea when certain words or phrases came into common use. One caveat is that you have to choose your search terms carefully -- for example, the phrase "Civil War" does not necessarily refer to the conflict of 1861-65.