Did people in the the 1950s in America say they wished they lived in the roaring 20s? Or is this a more modern phenomenon?
This is so common a sentiment it is difficult to limit one's discussion of it. It is also mixed in with the simpler idea of "the grass is greener on the other side"; for example, the opening of Horace's first satire,
How come, Maecenas, no one alive’s ever content
With the lot he chose or the one fate threw in his way,
But praises those who pursue some alternative track?
Taken broadly, this is a pretty trite idea, mixed up with all kinds of moralizing, lazy nostalgia. Again from Horace,
Slow, long in hope, still eager to live on
And fond of no man's judgment but his own:
On youth's gay frolics peevishly severe,
And oh! when he was young, what times they were!
The flow of life brings in a wealthy store,
The ebb draws back whatever was brought before,
And leaves a barren sand and naked shore.
(the old man's point of view can be found in Juvenal's satires). Or Burke's notorious outburst about the French Revolution:
But the age of chivalry is gone; that of sophisters, economists, and calculators has succeeded, and the glory of Europe is extinguished forever.
The idea of a lost golden age, however, is deeply connected to myths / superstition / etc. and is common to many religions. there has also been various attempts throughout history to divide the world up into "ages," usually of descending merit, from Hesiod to Vico (a view of the middle ages can be found here).
Romanticism probably gave it the most signficant, modern boost (being in a way the revival of religious feeling and ritual in a secular—cultural—context, even if the idealism was only wished for not believed in). The romantics were, very generally, disgusted with the materialism of the modern world and sought refuge from it wherever they could, obsessing over their own "belatedness" (e.g. Byron's Childe Harolde lamenting the ruins of Europe), not caring often to identify exactly when or where they would prefer to be. But, conventionally, the argument over the superiority of the past or the present (or the future, or one's dreams) had existed for a while; this sense of wishing to have lived elsewhere is central of course to the Renaissance, in the revival of learning, the desire to re-create "the republic of letters" (modelled on various ancient institutions—Plato's Academy, the Alexandrian Pleiade) as well as in art. Petrarch, historically situated at the turning point between the middle ages and the Renaissance, and whose sonnets were just a hobby compared to his innovative scholarly work, resented the ignorance of the time he lived in, nostalgic for the then neglected golden age of Roman literature.
There were some contentious literary debates in late 17th century over the relative merits of the literature of the moderns and the ancients, as satirizied in Swift's Battle of the Books; and it was a typical topic of conversation, as seen in Boswell's Tour of the Hebrides: "'In such houses,' said he, 'our ancestors lived, who were better men than we.' 'No, no, my lord,' said Dr Johnson. 'We are as strong as they, and a great deal wiser.' This was an assault upon one of Lord Monboddo's capital dogmas." But Johnson's position here, on our relative "wiseness," which Bacon paradoxically put as—the moderns were the real ancients and the ancients mere children in comparison, was just what annoyed the romantics. Rousseau's position that literature and science have not benefited man, and that one must imagine even the savage noble, disrupted the enlightenment's idea of cultural perfectability (which was different from cultural meliorism—where the emphasis is not on a teleogical, platonic purity but innovation or novelty—which is rather decadent or naturalistic than classical). Chateaubriand said that modern man was overwhelmed by second hand experience—meaning that he has exhausted life in learning about it before he ever got around to enjoying it, and therefore is incurably melancholy and misanthropic. This quickly became an essential if not the essential fictional romantic convention, mutating from the more philosophical theme of satiety in Goethe's Faust to the extravagant ennui of Byron's Manfred, and then continuing in various guises all the way up until Hemingway—having been featured, if only ironically, in the work of a large amount of the significant writers in between—Stendhal, Baudelaire, Huysmans, Lermontov, Dostoevsky, Wilde, Joyce, Eliot, etc. (the quintessential quote re: romantic contempt for everyday life: "Living? Our servants will do that for us"). The most prominent ideal soon became, not the orient or the classical world, but the middle ages, the age of "romance," of the crusades and the holy grail.
Incidentally, the political attitude "romanticism" represented—wishing you were born at another time—is an extremely interesting subject; its development from the wild intuitions of Chateaubriand, Carlyle, and Victor Hugo, where the focus is on the mystical, grotesque side of the middle ages, to the scholastic, dogmatic pronouncements of the modernists T.S. Eliot and T.E. Hulme, who claimed that actually the middle ages were classical, because they had no conception of progress, and romanticism exploitative and lazy, "spilt religion." The middle ground is maybe found in Ruskin's concept of the gothic, which mixes a respect for the grotesque, the inherent "imperfection" of man (the revival of original sin later being Hulme's central idea), with voluminous explanations of the allegorical significance and superiority of the medieval attitude, all delivered in a Carlyle-derived deliberately idiomatic (i.e. non-classical, archaizing), moralistic prose style. This was very popular and influential, inspiring William Morris and the medievalism of the arts and crafts movement. Eliot was the most influential high-brow cultural critic from the 20s until nearly the 70s, and his most famous work, The Wasteland, is about the sterility of the modern world.
Also relevant to nostalgic views of cultural degeneration—Max Nordau, Spengler, Henry Adams, Leavis, the Southern Agrarians, Lewis Mumford, D.H. Lawrence, Ezra Pound, Henry Miller. It is important to remember, however, that the opposing, progressive viewpoint was always prevalent too (arguably dominating, being capitalistic), and the two were not always easy to seperate. And in relation to people wishing they lived only a decade or two previous, this is definitely a very old thing too, especially when the period gives rise to some kind of cultural myth—the naughty nineties, reign of Louis XIV, first few generations of romantics / decadents, etc. Woody Allen's Midnight in Paris is about this elusive cultural ideal, and could just as easily have been centred on New York. People were nostalgic in the 20s for the lost greenwich village of the 10s; Ezra Pound was dismissive of London in the 10s and Paris in the 20s; and plenty of writers in the 50s wanted to return to the more individualistic, now mythical 20s—Mailer, Vidal, Harold Rosenberg, Dwight Macdonald.
After such knowledge, what forgiveness?
I was born to be emperor of Cochin-China, to smoke pipes 36 fathoms long, to have 6,000 wives and 1,400 minions, scimitars to cut off the heads of people whose faces I don't like, Numidian mares and fountains of marble; and I have nothing but immense, insatiable desires, an atrocious ennui and yawnings with-out end
I would have liked to annihilate the creation and fall asleep with it in the infinite of nothingness; why could I not awaken among the flames of burning cities! I would have liked to hear the rattling bones that crackled in the fire, to cross rivers filled with corpses, to gallop over prostrate nations and crush them with the four iron hooves of my horse, to be Gengis khan, Tamerlane and Nero.
Our age has no form of its own. We have impressed the seal of our time on neither our houses nor our gardens nor anything that is ours. On the street may be seen men who have their beards cut as in the time of Henry III, others who are clean shaven, others who have their hair arranged as in the time of Raphael, others as in the time of Christ. So the homes of the rich are cabinets of curiosities: the antique, the Gothic, the taste of the Renaissance, that of Louis XIII, all pell-mell. In short, we have every century except our own—a thing which has never been seen at any other epoch: eclecticism is our taste; we take everything we find, this for beauty, that for utility, this other for antiquity, such another for its ugliness even, so that we live surrounded by debris as though the end of the world were at hand.
It was at Godwin’s that I met him with Holcroft and Coleridge, where they were disputing fiercely which was the best—Man as he was, or man as he is to be. ‘Give me,’ says Lamb, ‘man as he is not to be.’