“The length of time from the American Revolution climax in 1781 until the Civil War climax in 1863 was 82 years. The next climax in 1944 was 81 years after the Civil War climax. Therefore, we can expect a climax to this current Crisis sometime in the 2025 range.”
So now I need to look up what happened around 1620 and 1700.
The book, The Fourth Turning primarily uses the Anglo/American history of the past 500 years in England and the US to illustrate the cycles of history.
They do discuss events farther back into Roman and pre-Roman times, but the past 500 years is sufficient to establish their thesis.
Excellent book for those who have read it. It doesn't seem to change anyone from liberal to conservative, or from conservative to liberal, and you can't tell if the researchers are liberal or conservative.