America and the “Splinter Cultures”
I've started reading Albion's Seed by David Hackett Fischer (about the fact that the British colonial settlers of North America were not a homogeneous group and could be divided into Puritans, Cavaliers, Quakers, and Borderers) and it sounded familiar. It resembles the Splinter Cultures of the Dorsai series by Gordon Dickson. The Friendlies were an analog of Puritans, the Cetans were an analog of Cavaliers, the Exotics were an analog of Quakers, and the Dorsai were an analog of Borderers.
One lesson we can learn from it is that the US was multicultural from the start.