Last year, believe it or not, was the year of Utopia. A perfect society: happy, prosperous, tolerant, peaceful – this idyll was widely commemorated, although its location, appropriately, was nowhere (from the Greek ou-topos: U-topia). The occasion was the 500th anniversary of Thomas More’s Utopia, a “splendid little book” (in More’s words) that, over the centuries, has found echoes in innumerable dreams and schemes, especially on the left.

Socialism has always harboured utopian visionaries, although they have not always been welcome there. From the “communities of universal harmony” sponsored by Robert Owen, Charles Fourier, Henri de Saint-Simon and their early 19th-century followers (dismissed by Marx and Engels as “purely utopian”); to the libertarian-communist Edens of William Morris, Edward Carpenter and other fin de siècle New Lifers; to the free-loving, free-living arcadias of 1960s radicals, utopianism has been alternately embraced and repudiated by the left. The scope of socialist aspirations has widened and narrowed with changing times. Today, in a climate of ascendant neoliberalism and far-right populism, the aspirations have dwindled to the point where even the modest social-democratic ambitions of Jeremy Corbyn and his followers are slated as “cranky utopian fantasies” by their Labour party detractors.

All socialist utopias involve some refashioning of gender relationships. This has been true from the start. Between 1825 and 1845, Britain’s first socialists – the “Owenites”, after the capitalist-turned-communist Owen – produced a root-and-branch critique of women’s oppression along with strategies to eradicate it, ranging from practical measures such as reform of the marriage laws and the introduction of birth control, to the creation of communities where private property would be abolished, childcare collectivised and nuclear households replaced by “cooperative family arrangements”. With these changes, the Owenites promised, women, married or single, would become men’s social equals; no woman, with or without children, would need a man in order to survive. Or, as one woman told a socialist meeting in 1840: “When all should labour for each, and each be expected to labour for the whole, then would woman be placed in a position in which she would not sell her liberties and her finest feelings.”

Libertarian-communist Eden … Edward Carpenter at Millthorpe, near Sheffield. Photograph: Courtesy of Verso

In the 1830s, Owenite feminism travelled from Britain to the US via Owen’s son Robert Dale Owen, a strong believer in women’s reproductive rights, and the celebrity freethinker Frances Wright. A handful of communities were established where marriage was by joint declaration, with no swearing of eternal fidelity or wifely obedience. These communities were short-lived, as were the half-dozen Owenite communities in Britain, and by the late 1840s the movement had died out. But the links between utopianism, socialism and feminism survived to re‑emerge in the 1880s, strengthened by the rise of the women’s suffrage movement in the intervening decades.

A host of thinkers and organisations appeared in Britain and America dedicated to building a new Jerusalem free from “sex slavery”. The US east coast was especially rich in visionaries. Most were obscure, with few adherents and few traces left behind them. But in the mid-1970s, Sheila Rowbotham found a little book in the British Library written by one of them, Helena Born, who originally came from Bristol, and edited by an American named Helen Tufts. Later she discovered that Tufts had kept a personal journal. These findings set her on a four-decade search that has resulted in Rebel Crossings, a collective biography of a half-dozen transatlantic radicals of the late 19th century.

Rowbotham is a leading feminist historian, and an unapologetic utopian. Rebel Crossings opens on a personal note: “I first discovered the little group of rebels in this book when I, myself, was young and convinced the world was about to change for the better.” Now in her 70s, Rowbotham came of age politically in the salad days of the New Left, when young lefties like her were “seeking an alternative to communism under Stalin”. She looked for her alternatives in the campaign for nuclear disarmament, in the History Workshop movement and, above all, in women’s liberation, which became for her, as for many leftwing women at the time, her political home.

New Left men could be pretty old-school when it came to women. In 1969, Rowbotham published an influential pamphlet attacking the marginalisation of women by the “male-dominated revolutionary left” and arguing for feminism as a “whole people question”: “Our liberation is inextricably bound up with the revolt of all those who are oppressed [and] their liberation is not realisable fully unless our subordination is ended.” The following year she faced down an audience of (mostly male) students who laughed at her call for research into women’s history. In the decades since, she has published dozens of books and articles chronicling the histories of women, especially female freethinkers such as those in Rebel Crossings.

I met Rowbotham in those early days in the women’s movement. She had just published her first book – Women, Resistance and Revolution (1972) – which changed my life. I was a PhD student writing a boring dissertation on the US liberal philosopher John Dewey. I read her chapter on “Utopian Proposals”, ditched Dewey, and embarked on a study of utopian socialism and feminism in Britain (published as Eve and the New Jerusalem in 1983 and reissued last year).

‘Subversion sustained by humour and enjoyment’ … Sheila Rowbotham. Photograph: Martin Godwin/The Guardian

For Rowbotham, history writing was not an academic exercise but a political act: her declared purpose in writing Women, Resistance and Revolution was to produce a work that would aid the “continuing effort to connect feminism to socialist revolution”. Today her hopes for a socialist revolution have faded, but the ambition to link the past and present in radical ways is still present. “My aim,” she writes in Rebel Crossings, “is subversion sustained by humour and enjoyment.”

Born and Miriam Daniell were friends in 1880s Bristol who campaigned for women’s suffrage, aided local strikers and played leading roles in the Bristol Socialist Society. Robert Nicol was a Scottish union militant and Miriam’s lover. In 1890, the three young people migrated to Boston, Massachusetts, where they experimented with a host of isms, including Marxism, anarchism, transcendentalism and something called “ownerism” (“self-ownership”). They read Emerson, Thoreau, Carpenter, Charlotte Perkins Gilman, Walt Whitman (a special hero), and wrote for journals with titles such as Liberty, the New Age and the Coming Light.

Charismatic and bold … Miriam Daniell. Photograph: Courtesy of Verso

Miriam – gorgeous, charismatic and the boldest of the trio – embraced Russian nihilism and a mystical feminism centring on “woman as the universal redeemer”. Helena, a more tough-minded individual (“fearless and repellent” was her self-description), became the “directing liberator” of the Boston Comradeship of Free Socialists and wrote articles denouncing capitalist alienation and feminine fripperies. Both women were bravely defiant of social convention: Miriam had left behind a husband in Bristol, while Helena became the lover of a married man, an Irish-born anarchist named William Bailie.

Both also died young: Helena in her early 40s, Miriam in her mid-30s, after giving birth to a daughter named Sunrise, a “small, helpless bundle of utopia” who became the stepdaughter of the socialist novelist Gertrude Dix, who succeeded Miriam as Robert Nicol’s lover. After Helena’s death, William Bailie married Helena’s friend Helen Tufts, a Boston-born feminist who in the 1920s was expelled from the Daughters of the American Revolution for exposing a DAR blacklist of social reformers and other “anti-patriots”. “If that’s patriotism,” she bit back, “I’ll have none of it.”

Rebel Crossings vividly evokes these busy, entangled lives, with their campaigning and propagandising and romancing, criss-crossed by doctrinal disagreements and ethical dilemmas made more acute by relentless soul-searching and grasping at moral absolutes. All six of Rowbotham’s protagonists were religious freethinkers, but their radicalism was shot through with the missionary zeal of a spiritual elect. “Dear Comrade,” Miriam wrote to a friend, “let us if we think we see higher heights and purer lights than another not shun that climbing Soul … but bend to point the way we take.” Pragmatism had little part to play here, including in their free-love commitments, which were passionately ideological. “Love … waits not upon social or political changes,” Helena wrote to William at the height of their romance. “It creates them. Love is the great equaliser.”

She vividly evokes these busy, entangled lives, with their campaigning and propagandising and romancing

But if love equalised hearts, it left many social inequities intact. “Beyond all teaching and preaching is actual living,” Tufts reminded her comrades. But actual life often disappointed, as new world modes of relating bumped up against old world habits and attitudes. Jealousy, rivalry, prejudice raised their heads; low “bodily needs” got in the way of the higher life, especially for the women. A woman who behaved “as though her rights were equal to man’s” would be treated equally, Helen maintained; but daily life with her William was not always an egalitarian dream. “Wm hardly ever wipes the dishes, but he says ‘I can’t understand where all these dishes come from!’” she confided to her journal. “My dearest would like to forget dishes after he has used them.”

It’s easy to smile at some of this, and Rowbotham does smile now and then. But she never condescends. These were brave spirits whose courage she admires, and whose “struggles to balance altruistic service and egoism, union and personal desire” earn her sympathy. And her empathy: she has known such struggles. She has lived them, or rather experiences very like them – as have I, and many other women who share our political past.

For any veteran of 1970s socialist feminism, reading Rebel Crossings is likely to be a mixed pleasure, summoning up a radical past that feels sadly distant yet uncomfortably close, as it reawakens memories of our own utopian moment, with its courage and confusions, its open-hearted visions and myopias. Like the book’s protagonists, we knew what we wanted – a world where all would live freely and unselfishly, with equal status, resources and opportunities – and we sought to live our lives in the shape of our ideals, forming “anti-patriarchal” sexual relationships and communal households intended to prefigure the egalitarian society to come.

A women’s march in Sydney, Australia, on 21 January. Photograph: Dan Himbrechts/AAP

We were “whole life” revolutionaries, and the future belonged to us. But we underestimated the inequalities among us (of class, race, cultural advantage, financial resources) and the obstacles we faced, both internal and external: our conflicting desires (for unity, independence, work, children); our muddles over men; the personal hostilities, disguised as political disagreements, that cut across sisterly solidarities; but above all, the relentless momentum of our times, as the postwar settlement that had kindled our optimistic dreams gave way to tooth-and-claw neoliberalism and the dystopian nightmare we now see before us.

Rebel Crossings is crammed with hopeful visions from the past, but on the present it strikes a melancholy note. Watching globalised capitalism in action – “appropriating free expression, raiding collective spaces, shredding non-marketable aspirations, social solidarity and fellow feeling” – Rowbotham is forced to recognise that “a good society, along with a new radical and emancipatory social consciousness, will take longer to realise that I imagined. Like many in my generation, I accept this reality rationally, but emotionally find it ineffably baffling.”

In the wake of 2016, Rowbotham’s bafflement is widely shared – and not just by one-time utopians. And yet … last month some five million women took to the streets in 673 marches worldwide. On seven continents we marched, against Trump and all that he represents: demagoguery, xenophobia, misogyny, racism, sexism, homophobia. Our banners echoed the call of Rowbotham’s long-ago rebels, for a future of “liberty, love and solidarity”. For most of us, this was the first glimmer of light in a dark time. Hardly utopia, but a moment of genuine hope, born not in some nowhere land of political fantasy but here and now, in this “very world, which is the world of all of us” (Wordsworth) – the only place from which real hope, and determination, can spring.

• Rebel Crossings: New Women, Free Lovers and Radicals in Britain and the United States is published by Verso. To order a copy for £21.25 (RRP £25) go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.