Have you ever seen one of those old, black-and-white American movies or television programs from the 1940s or '50s? And did you notice something peculiar about most of the men in those shows?

Every one of them, it seems, is wearing a hat -- often a snap-brim, felt variety called a "fedora." There's Humphrey Bogart in Casablanca, burly Broderick Crawford in the TV show Highway Patrol, and gossip columnist Walter Winchell -- all with hats firmly attached to their heads -- not just on the street, but even inside, in the office.

Chicago Sun-Times columnist Neil Steinberg found this so engrossing that he wrote a whole book on the subject. Mr. Steinberg says wearing a hat was simply expected. It was the style, like it or not, in an era of rigid conformity. Different varieties of hats sent different social messages. And after all, a man had to have a hat that he could tip when a woman passed him by.

Neil Steinberg's book title, Hatless Jack,  refers to the youthful, popular President John F. Kennedy, who is often accused of dooming the men's hat industry by delivering his 1961 inaugural address without the usual top hat. In truth, Kennedy did wear the formal hat on the ride to the inaugural and through most of the festivities.

Instead, it was women, who began wearing barettes and little sprigs of flowers and such instead of clunky hats, and thousands of soldiers, returning from World War II, where their heads had been stuffed into military caps and helmets, who fomented the idea that hats were a nuisance.

If you look at the photo that goes with this "Only in America" site on the VOA website, you'll see that the author is wearing a sort of Louisiana swamp hat. That's because these days, wearing a hat is fun, and quite optional.

Hatless Jack: The President, the Fedora, and the History of American Style is published by the Plume Book division of Penguin Books.