Introductions to books can be revealing, though not necessarily in the way the author intends. Take The Great Trials of the Twenties: Why do the authors have to tell you what's in a non-fiction book and why it matters? Maybe because if you don't finish the book, you at least know what they were trying to do? Seems defeatist.
On the other hand, I could use the help when I read oblique fiction or (especially) poetry. But they usually don't have introductions.
Well, anyway, this is a textbook about some legal cases you've mostly heard of. Sets out the facts in an evenhanded way. Avoids controversial conclusions. Some worthwhile background, such as the argument for putting John Scopes on trial. But not my idea of casual reading. Few if any anecdotes, and even the dictionary contains humor.