While Dickinson didn't publish a single book of poems during her lifetime, her complete poems are often considered her magnum opus. This collection, compiled and published posthumously, showcases her distinctive voice, profound insights, and innovative use of language.
It's worth noting that some critics argue that certain individual poems, like "Because I could not stop for Death" or "Hope is the thing with feathers," are strong contenders for her magnum opus.
Ultimately, the choice of Dickinson's magnum opus depends on individual interpretation and appreciation. However, it's safe to say that her entire body of work, collected in her complete poems, is her most impactful and enduring contribution to literature.