Look at “The Cousin’s Wars”, author escapes me at present, but he makes the same point across the English Civil wars, the American War of Independence and the US Civil War.
Lots of good info there as well as in “Albion’s Seed, Four British Folkways in North America”.
The first book makes the case for a series of conflicts with roots in the differences related in the second (different authors).
Personally I wouldn’t be surprised at a fourth in the series in our future, many of the differences in world view present in our body really are intractable.
Kevin Phillips, as I recall. I read it when it came out, I think early ‘90s. Good book, and quite interesting. They trace the family lineages and it shows how the same peoples fought each other in the English civil war, the American Revolution and the American Civil war. The main difference is that in the Revolution, the Cavaliers in the US joined with the Puritans, which allowed this nation to be formed. They two have been fighting ever since, and the Scots-Irish and midwestern Germans have been joining one or the other to create a majority ever since.