A few months ago, Tim Lee, Zack Beauchamp, and Matt Yglesias brought you 40 maps that explain World War I. This chart makes for a nice addendum to those:
When the Great War became World War I, in one chart


The chart, by Mic’s Jared Keller, shows usages of various terms for the war in books digitized by Google, as gleaned from Google’s Ngram search tool. What’s intriguing is that references to World War I began increasing even before World War II began in Europe. The big growth obviously came as the war began and after its conclusion, but this suggests that in at least some texts, “World War II” was used in the same ominous, premonitory way that “World War III” is today.
Update: David Taylor strikes some important notes of caution here — smoothing means that data from 1936 includes references from 1933 to 1939, and Google Books isn’t always great about identifying dates, which both limit the usefulness of the data. His whole post is a great exploration of how Ngram works; I encourage you to check it out.











