Although today the 1920s seem consigned to the distant past—a black-and-white time before televisions, cell phones, and computers—the fashions, foibles, and problems of that decade can still be seen in modern times. Then, as now, adults complained about the loose morals of the younger generation and their love of silly fads, crazy music, cigarettes, and illegal substances. The stock market soared to unprecedented heights and skidded to precipitous lows, wiping out the fortunes of average Americans who bought stocks that were ridiculously overvalued. Like the illegal drug trade today, Prohibition allowed violent gangsters to make millions of dollars by supplying a dangerous drug— in this case, alcohol—to insatiable consumers who refused to remain sober. And, unfortunately, racial prejudice and fear of foreigners were problems then and remain so today.

By looking past flapper fashions, rickety Model T...