At the time of his death in 1935, Edwin Arlington Robinson was commonly thought to be the greatest modern American poet. President Theodore Roosevelt had announced years earlier that Robinson’s “poems will be as alive 2,000 years hence as they are today.” The chief mystery confronting us is not the generosity of such assessments but the unexpected decline Robinson suffered in the intervening years. Robinson’s reputation did not merely diminish — it nearly disappeared in the lengthening shadows cast by titans like T.S. Eliot and Robert Frost. Perhaps Robinson has simply fallen victim to the capricious cycles that affect literary reputations, and it may be time for a Robinson revival. Thus it is with superb timing that we have Scott Donaldson’s inclusive and engaging new biography, “Edward Arlington Robinson: A Poet’s Life” (Columbia, 554 pages, $34.95), which develops a strong case for Robinson as “our first truly modern poet” and provides ample evidence for his restoration to the pantheon of American poetry.

Robinson labored in obscurity for years. By the time he paid to have his first book published at the age of 26, his precocity was impossible to ignore. One critic of the slim debut remarked that Robinson saw the world as a “prisonhouse,” moving Robinson to reply: “The world is not a ‘prison-house,’ but a kind of spiritual kindergarten, where millions of bewildered infants are trying to spell God with the wrong blocks.” Such grim observations were routine for Robinson. He once wrote to a friend, apologizing for his glum appearance in a photograph: “I have a look that might lead one to think that I had just been eating the lining of my own coffin.” The bleakness and poverty of the first half of his career was redeemed by prodigious renown and financial success in the second half.

Robinson modernized poetry without thinking of himself as a modernist. He rebelled quietly, without manifestos or bravado, against the predictable confections of his day. At the close of the 19th century, poetry had become a “parlor game for the wealthy,” and it was into these parlors that Robinson stole with disturbing poems of failure and suicide. Although he modernized the language of poetry by simplifying it and removing Victorian embellishment, he never embraced the free verse espoused by Ezra Pound and Amy Lowell, joking, in typically modest fashion, “I write badly enough as it is.” By the end of his life, the former innovator was inclined against all things modern, going so far as to grumble about “free verse, prohibition, and moving pictures,” which he felt worked to “abolish civilization.”

Painfully shy, Robinson was described by his contemporaries as “unapproachable,” “buttoned-up,” and “notoriously reticent.” One handwriting expert declared that Robinson’s cramped script (he never felt comfortable using a typewriter) suggested “an unusual degree of repression.” After a painful early romantic experience, which involved an awkwardly expressed love for a woman who soon afterward became his sister-in-law, he remained a bachelor. His career enjoyed numerous boosts from dedicated friends in New York, Boston, and his hometown of Gardiner, Maine. The most famous of these supporters was Roosevelt, who, in 1905, learned of the struggling poet from his son, Kermit. The president was an avid reader — devouring a book daily, according to some accounts — and offered to help Robinson in any way he could. He located a sinecure for Robinson in a Lower Manhattan customs house and even went so far as to review Robinson’s books in Outlook, the only known example of literary criticism by a sitting president. A duly grateful Robinson said that Roosevelt “fished me out of hell by the hair of my head.” Unfortunately, the four years at the customs house were perhaps the least productive for Robinson. He believed the struggles that characterized his younger years had inspired him.

Robinson transmuted friends, strangers, and public figures into characters for his poems. One critic identified 233 fully formed characters in Robinson’s poems. This would be a feat for a novelist and is almost unheard-of for a poet. Just as Edgar Lee Masters created “Spoon River,” Robinson invented “Tilbury Town,” populated by the “defeated people” with whom he identified so strongly. He once remarked that he had “always been unhappy,” and that he was born with his “skin inside out,” so it was only natural that he put something of himself into characters like “Captain Craig,” the aging man of letters, “weak, dizzy, chilled, and half starved,” and Miniver Cheevy, who “wept that he was ever born, /And he had his reasons.” One anecdote provides an insight into the degree of scrutiny he brought to bear on his poems. An energetic young novelist, new to the MacDowell artists’ colony, where Robinson spent the last 23 summers of his life, asked Robinson how much he had accomplished that day. The poet answered: “This morning I removed the hyphen from hell-hound. And this afternoon, I put it back.”

Robinson’s triumph is largely one of scale. From modest propositions — a penniless aunt, forlorn clerks, a lonely drunk — he draws profound conclusions. He crafts universal scenes of suffering and survival with a combination of instinctive compassion and tremendous technical virtuosity. The poet Vachel Lindsay identified Robinson as a “novelist distilled into a poet,” and it is hard to improve upon this description. Mr. Donaldson’s close readings of the poems are masterful and edifying. He is able to open up the most difficult poems in remarkable ways, and this makes the biography an ideal companion to the new Everyman Library edition of the selected Robinson poems (256 pages, $12.50), also edited by Mr. Donaldson. Together, these two volumes will go a long way toward helping Robinson’s poetry survive what he described as “Art’s long hazard, where no man may choose / Whether he play to win or toil to lose.”

Mr. Hilbert is the editor of the Contemporary Poetry Review.