The Wealth of Nations, by Adam Smith, was the 2nd most important publication in 1776. The original publication was over 900 pages in 2 volumes and basically explained economics. Specifically, market economies.
Having seen this book mentioned throughout my life, I decided to read it. OK, I actually listened to an audiobook version. I'm glad I did that because 18th century English is not my native tongue and hearing it is much easier to understand than reading it. I've mentioned this sort of thing before, when I listened to Paradise Lost.
The book was actually interesting, although I confess to having pressed the "next track" button on the CD player a few times. It was fascinating to listen to the (very understandable) explanations of the economics of making nails by a lone craftsman, then by a group of specialists, then on to factories and farms, and finally to nation states.
I think Smith had a somewhat naive view of the effects of self-interest, but it's interesting to see how it all started (or at least, was famously codified). If you're interested, here's the version that I listened to. It's abridged and that wins it 1.5 stars from 3 Amazon reviewers.
So then, just in case I missed something, I listened to this outline of the book by political satirist P.J. O'Rourke. It has better reviews on Amazon, but I enjoyed it less. It did point out areas where Smith contradicted himself (understandable for a 900+ page book) and where Smith's arguments or explanations are just plain odd. Like the part where Smith describes how a beaver is worth more than a deer to a trapper: "If, among a nation of hunters, it usually costs twice the labor to kill a beaver which it does to kill a deer, one beaver should naturally exchange for or be worth two deer." O'Rourke humorously points out: "Can killing a beaver really be twice as hard as killing a deer? A deer can run like hell. We know where the beaver lives..."