THE Roaring ’20s was the decade when modern celebrity was invented in America. F. Scott Fitzgerald’s “Great Gatsby” is full of magazine spreads of tennis players and socialites, popular song lyrics, movie stars, paparazzi, gangsters and sports scandals — machine-made by technology, advertising and public relations. Gatsby, a mysterious bootlegger who makes a meteoric ascent from Midwestern obscurity to the palatial splendor of West Egg, exemplifies one part of the celebrity code: it’s inherently illicit. Fitzgerald intuited that, with the old restraining deities of the 19th century dead and his generation’s faith in man shaken by World War I, celebrities were the new household gods.

What are celebrities, after all? They dominate the landscape, like giant monuments to aspiration, fulfillment and overreach. They are as intimate as they are grand, and they offer themselves for worship by ordinary people searching for a suitable object of devotion. But in times of widespread opportunity, the distance between gods and mortals closes, the monuments shrink closer to human size and the centrality of celebrities in the culture recedes. They loom larger in times like now, when inequality is soaring and trust in institutions — governments, corporations, schools, the press — is falling.

The Depression that ended Fitzgerald’s Jazz Age yielded to a new order that might be called the Roosevelt Republic. In the quarter-century after World War II, the country established collective structures, not individual monuments, that channeled the aspirations of ordinary people: state universities, progressive taxation, interstate highways, collective bargaining, health insurance for the elderly, credible news organizations.

One virtue of those hated things called bureaucracies is that they oblige everyone to follow a common set of rules, regardless of station or background; they are inherently equalizing. Books like William H. Whyte’s “Organization Man” and C. Wright Mills’s “White Collar” warned of the loss of individual identity, but those middle-class anxieties were possible only because of the great leveling. The “stars” continued to fascinate, especially with the arrival of TV, but they were not essential. Henry Fonda, Barbara Stanwyck, Bette Davis, Jimmy Stewart, Perry Como, Joe DiMaggio, Jack Paar, Doris Day and Dick Clark rose with Americans — not from them — and their successes and screw-ups were a sideshow, not the main event.