The episode begins with the Pilgrims landing at Plymouth Rock in Massachusetts. They spoke the way the people in the south of England spoke. And they didn't borrow many words from the local Indians because they were all walled up behind their palisades. No one could apply the words, "O ye of little faith" to them. They had faith in abundance. Everything was a sin, and the likable Melvyn Bragg lists some of them for us. If those laws were still in effect, we'd all be in the stocks, including the judges.
The New Englanders grew to feel that, backed by their faith and their sense of calling to community service, they were in a position of some authority. And they weren't ashamed of it. That's one of the reasons we get so many presidents from Massachusetts. Anyone interested in American aristocracies ought to check out E. Digby Baltzell's "Puritan Boston and Quaker Philadelphia." Noah Webster's first American dictionary of 1828 changed the pronunciation and spelling of many English words. (Honour < honor; "forrid" became "fore-head.") He gets a bit into the Gullah dialect of the islands off the Georgia coast but it's the demonstration of a dying way of speaking. Those island are now spotted with extraordinarily expensive mansions and cheaper condos.
Bragg is informative with regard to all of the lingo picked up on steamboats on the Mississippi and Missouri, where gambling was a common pastime or business. "The buck stops here," "cash in your chips," etc.
And many words and phrases were borrowed from Spanish along the Mexican frontier. Lasso, pinto, rodeo, and so forth. He doesn't mention it but Spanish vaquero gave us the mangled buckaroo in English.
It's as good as any of the other episodes, which is saying a lot because they've all been exceptional.