In the spring of 1935 the country was caught up in a get-rich-quick scheme that enraged mail carriers and postal officials. The chain-letter craze clogged post offices, burdened letter carriers, and dominated public conversation. The chain letter featured a list of six names. Recipients of a letter were asked to send a dime to the person at the top of the list, scratch that name out, add their own at the bottom, and send the letter on to five friends. Presumably, after five such progressions, the individual's name would reach the top of the list, and they would be deluged with 15,625 dimes — $1, 562.50 — no small sum during the Depression. Of course, if anyone broke the chain, the payoff became uncertain, and while the basic premise was preposterous, millions of Americans participated in the scheme. Post offices had to hire extra help to process...