This came recommended at the end of Mr. Money Mustache's blog post about crypto-currencies, and I was immediately impressed by the depth and detail in Smith's historical account of the creation and evolution of the stock market.
His notes are incredible and more functional than just naming the "who" and the "when", he really explains how these events marked the times and helped push forward the constant understanding of the entire market system.
He captures every market player that I'd even tangentially heard of, even the ones that I'd forgotten from my business school days - JP Morgan, Clarence Barron, Fischer Black and Myron Scholes, Charles Dow, Charles Merrill, Warren Buffet, all the way to Peter Lynch and Alan Greenspan (the book was written in 2001). Somehow John Bogle didn't make the cut, but that can be forgiven, I suppose.
I'm not sure what I learned that can be applied now, but that's kind of the point. Everyone is still learning so much and there are so many mysteries regarding the human element and how it affects the stock market, but it's somehow comforting to know that the history of the market has constantly evolved to be more transparent and rational while maintaining its exuberance.