“Poets in our civilization,” T.S. Eliot writes in a 1921 essay, “must be difficult.” Such difficulty, he believed, reflected the times: advanced industrialization transformed the West, Europe reeled from World War I, and the Bolshevik Revolution ignited Russia. Thinkers such as Darwin, Nietzsche, Marx, Freud, and Einstein changed people’s understanding of history, economics, philosophy, science, psychology, physics, and even religion. “Our civilization comprehends great variety and complexity,” Eliot continues, and “this variety and complexity … must produce various and complex results.” With the inventions of everything from the automobile to the airplane, the vacuum cleaner to the incandescent lightbulb, the motion picture to the radio, and the bra to the zipper, people’s lives were changing with unprecedented speed. Many English-language artists, including poets, thought a new approach was needed to capture and comment on this new era, requiring innovation in their own work: the result was called Modernism, the largest, most significant movement of the early 20th century.

Difficult, various, complex: these are often the very terms critics use to describe Modernist poetry in general. T.S. Eliot’s The Waste Land is often seen as the acme of Modernist writing—so much so that William Carlos Williams later compared its publication in 1922 to “an atom bomb” dropped on the landscape of English-language poetry. The long, obscure poem exhibits many of the techniques associated with the movement: use of collage and disjunction, free verse, an unsentimental impersonality, and a dense web of references to both high and low culture. However, neither those gestures nor the poem’s apocalyptic atmosphere fully represents Modernist poetry, which is often, in its “variety and complexity,” difficult to read and to define.

One of Modernism’s most famous slogans is a case study in its contradictions. For later critics, “make it new” became a shorthand for the movement’s goals, especially its obsession with artistic novelty. But the phrase, attributed to Ezra Pound, wasn’t well-known to the Modernists themselves and, ironically, wasn’t itself new. In fact, it’s an ancient, a translation of a translation: according to the Confucian texts Pound took the phrase from, it was once emblazoned on the bathtub of the first ruler of the Shang dynasty.

For Pound, the it in “make it new” was perhaps not so much poetry as history. His magnum opus, The Cantos, is a case in point: it retells classical stories as it attempts to revitalize outmoded forms, such as accentual verse. Both a scholar and an agitator, Pound had a hand in many of Modernism’s decisive turns. In the 1910s, he dabbled in theories under the heading of futurism, and alongside H.D. and Amy Lowell, he founded Imagism, an early Modernist school crucial to the development of free verse. Pound’s friendships with W.B. Yeats and Eliot propelled both men toward the visionary, and Pound’s influence on dozens of writers helped define Modernism more than that of any other poet.

Not every Modernist poet thought as Eliot and Pound did. Wallace Stevens, another giant of the era, saw contemporary upheavals in a less pessimistic light. His lavish philosophical poems explore how poetry might constitute a “supreme fiction” that could take the place of organized religion. And Hart Crane positioned his varied, ornate epic The Bridge as a direct challenge to The Wasteland in an expansive, Whitmanesque vein.

Others sought a more decisive break with tradition. “Nothing is good save the new,” William Carlos Williams writes in the prologue to Kora in Hell. For him, the new meant jarring enjambment, vernacular language, and an improvisational style—innovations fueled in part by innovations in the visual arts such as cubism and the readymade. Marianne Moore mixed “plain American which cats and dogs could read” with quotations from a huge range of sources, and measured her jagged lines by syllable instead of stress. Some poets discarded the line altogether. Gertrude Stein, one of the earliest Modernist innovators, wrote prose poems that sought to focus readers on the sonic and associative textures of words. And E.E. Cummings seized on the potential of the typewriter, using the space of the page, the parenthesis, and even the individual letter in radically new ways.

Mina Loy also experimented with typography, but saw her male counterparts far eclipse her reputation. Her example raises questions about who is included in conversations about the movement. For instance: should Robert Frost, with his ear for both the vernacular and the iambic, be part of the story of Modernist poetry? Langston Hughes offers another limit case: is his blues prosody better understood as a Modernist achievement, or in the context of the Harlem Renaissance? What about such poets as César Vallejo and Anna Akhmatova, innovators outside the Anglo-American tradition? As with any far-reaching movement, individual artists rise above any particular tradition: not everyone’s work adheres to all the same principles nor does a movement’s output exhibit all the same styles and tendencies.

Such questions are crucial but vexing; more certain is Modernism’s legacy. The movement’s most immediate heirs were the Objectivists, whose varied writings extended the work of the first-generation Modernists starting in the later 1920s and ‘30s. But the influence of the Modernists extends well into the postwar period. Charles Olson’s influential 1950 essay “Projective Verse” consciously aligned the Black Mountain School and the later San Francisco Renaissance with “the experiments of Cummings, Pound, and Williams,” but they would “make it new” by innovating their own poetics to address their different times and culture. The formidable effects of Modernism are also measurable by later reactions against them, the postwar turn towards Confessionalism in particular.

The following selections of poets, poetics essays, poems, articles, poem guides, and audio recordings are intended as an introductory sample of the Poetry Foundation’s offerings on Modernism; they cannot be an exhaustive representation of the school’s many and varied aspects.