But if the ’50s weren’t much fun to live through, they turn out to be a lot of fun to read about. Tainted fun, I-shouldn’t-be-enjoying-this fun, but fun all the same. Cars guzzled gas, soulless suburbs bloomed, “Ozzie and Harriet” reigned on TV and political correctness meant voting a straight Republican ticket. If the Dulles brothers felt like overthrowing the government of Guatemala to protect the interests of United Fruit, nobody said boo. And what wasn’t evil was lurid and trashy, from Elvis to the TV quiz-show scandals to car designer Harley Earl, the tail-fin king.

The big exception to all the nefariousness and trivia was the birth of the civil-rights movement, and here Halberstam tells a story that is unironically triumphant. Its heroes were without tarnish, from Rosa Parks to the black students of Little Rock to Chief Justice Earl Warren. The story did not lack villains, but it is the heroes who we remember because, in an amazing number of instances and against all odds, people did the right thing.

Rockabilly:The civil-rights chapters are also the best of Halberstam. He is neither a fine stylist nor much of a thinker, but he cut his teeth on these events as a young reporter, and he clearly still cares about the subject (his chapters on the auto industry and rockabilly benefit from a similar affection). As a result, these passages are stamped with an immediacy lacking in those chapters where the author falls back on secondary sources. In fact, a good way to read “The Fifties” is from back to front, using the notes on sources as a guide. The sections where Halberstam did his own legwork are invariably better.

One of the most telling-and saddest-sections is based on an interview he conducted with Frederick Morrow, the lone black man in the Eisenhower administration. Summing up Morrow’s troubling tenure as a public servant, Halberstam reports, “When Morrow represented the President at a Lincoln Day ceremony in Topeka, Kansas, a woman came over near the end of the reception and told him, ‘Boy, I am ready to go now; go outside and get me a taxi’.”

Happily, Halberstam’s stories are not always so bleak. One place where blacks and whites met on a congenial equal footing was the radio. Disc jockeys like Dewey Phillips in Memphis (“Dewey was not white,” soul singer Rufus Thomas once said. “Dewey had no color”) wielded enormous power because they suddenly had an audience with relatively enormous wealth. The average teenager’s weekly income in 1956 was $10.55, roughly the disposable income of the average American family 15 years earlier.

In “The Best and the Brightest,” Halberstam used the theme of hubris to unite his story. No such big idea animates “The Fifties.” In fact, his thesis seems to be that there was no big idea-just a lot of changes big and small that, taken together, comprise a watershed in our history. It’s a plausible notion and it somewhat justifies his rambling narrative. All the same, it’s a pity Halberstam didn’t spend more time synthesizing his raw material. When he does, the insights are often fresh and illuminating. Describing the Little Rock school-desegregation case, for example, he points out that had not television cameras been there to beam the mob violence into the nation’s living rooms, the event would have had much less impact. Sociological and technological advances went hand in hand.

In the end, “The Fifties” resembles nothing so much as one of those tail-fin and chrome dinosaurs that once were the pride of Detroit. It’s a bit pompous looking, way too long and not all that efficient. But it’s loaded with narrative horsepower, and it’s almost sinfully entertaining. Just about the only thing it’s lacking is a pair of fuzzy dice.