The British Victorian Era in England and the USA's Gilded Age-Progressive Era (app. 1870s - early 1900s) is the most historically productive period for utopian literature, mostly fiction.
After the First World War, dystopian literature prevailed. (Brave New World, Nineteen Eighty-Four, Fahrenheit 451, Lord of the Flies)
The preceding Romantic era's utopian literature was more non-fictional or tract-oriented, with considerable experimentation in on-the-ground intentional communities. (19c American Utopias)
Utopian thinking and action in the 19th century was stimulated by rapid progress in sciences and social organization, with improved hygiene and nutrition, plus fossil fuels and imperialism leading to higher standards of living in much of Europe and North America.
The later 1800s saw the rise of social sciences (psychology, sociology, anthropology, more economics), propagating studies of human problems and theories for improvement.
19th-century utopias divided to two time-orientations:
Futuristic, sophisticated, technological, urban, hygienic (Looking Backward, 1887-2000)
Nostalgic, medieval, low-tech, pastoral / rural, native health (Erewhon, Herland, News from Nowhere, others)
Erewhon begins somewhat like Herland, with a single male traveler (Higgs) in a faraway land exploring a hidden valley beyond an apparently impenetrable mountain range.
Upon being gently captured in the highlands by attractive people resembling Italians, he is led through villages toward the city: "They were about as far advannced as Europeans of the twelfth or thirteenth century, certainly not more so."
His hosts are disturbed to discover Higgs's watch, and he visits a town museum where "the greater part of the room was occupied by broken machinery of all descriptions." Later, one of his instructors explains that "about fur hundred years previously, the state of mechanical knowledge was far beyond our own and was advancing with prodigious rapidity, until one of the most learned professors of hypothetics wrote an extraordinary book . . . proving that the machines were ultimately destined to supplant the race of man, and to become instinct with a vitality as different from, and superior to, that of animals, as animal to vegetable life," after which the country "made a clean sweep of all machinery that had not been in use for more than two hundred and seventy-one years (which period was arrived at after a series of compromises), and strictly forbade all further improvements and inventions . . . ."
An excerpt from that "extraordinary book" constitutes Erewhon's most famous passage, "The Book of the Machines" (chapters 23-25), which recent readers have interpreted as predicting the "technological singularity" whereby artificial intelligence will surpass human intelligence with all kinds of consequences for evolution and human or even cosmic destiny.
As in Herland, the opening chapters are written in a bright, quick style typical of an adventure story, describing a questing hero's ingenuity in mastering the unknown, e.g. a romance narrative.
After the explorer learns to speak with the utopians, the narrative diverges to observations and explanations akin to a tour-book or anthropological study, giving rise to philosophical speculation and satire.
Example of satire: Erewhonian attitudes toward crime and nature are reversed:
"This is what I gathered. That in that country if a man falls into ill health, or catches any disorder, or fails bodily in any way before he is seventy years old, he is tried before a jury of his countrymen, and if convicted is held up to public scorn and sentenced more or less severely as the case may be. There are subdivisions of illnesses into crimes and misdemeanours as with offences amongst ourselves—a man being punished very heavily for serious illness, while failure of eyes or hearing in one over sixty-five, who has had good health hitherto, is dealt with by fine only, or imprisonment in default of payment. But if a man forges a cheque, or sets his house on fire, or robs with violence from the person, or does any other such things as are criminal in our own country, he is either taken to a hospital and most carefully tended at the public expense, or if he is in good circumstances, he lets it be known to all his friends that he is suffering from a severe fit of immorality, just as we do when we are ill, and they come and visit him with great solicitude, and inquire with interest how it all came about, what symptoms first showed themselves, and so forth,—questions which he will answer with perfect unreserve; for bad conduct, though considered no less deplorable than illness with ourselves, and as unquestionably indicating something seriously wrong with the individual who misbehaves, is nevertheless held to be the result of either pre-natal or post-natal misfortune." (ch. 10)
Comparison to Herland and Looking Backward: A love-story romance is glimpsed at edges of chapters, leading to the book's ending with union or disunion between characters and / or traveler and utopia.
Comparison to Anthem: The utopia / dystopia restricts human invention for sake of social stability.