Walt Whitman’s “Leaves of Grass” was the book that grew up with America — literally.

During the course of the great gray poet’s 72 years, nine different editions would be published. What began as a slim volume of a mere dozen poems released on Independence Day, 1855, would expand to a plump compendium of 400 poems by the time of the 1892 “deathbed edition.”

This week, in honor of the 150th anniversary of its publication, the Library of Congress launched “Revising Himself: Walt Whitman and ‘Leaves of Grass,’” a modest collection of Whitman artifacts tucked between displays on memory and reason in the Library’s permanent American Treasures exhibition. “Revising Himself” explores the arc of Whitman’s life, from his early career as a teacher and journalist to his work in Civil War hospitals as a nurse and friend to young soldiers to his rise as the iconic

troubadour of nothing less than the American soul.

The organizing focus of the show is, however, “Leaves of Grass” in all its permutations, as Whitman molded it to fit his evolving vision, regrouping and renaming poems, rewording lines and altering punctuation from edition to edition.

Included in the exhibit are the only surviving manuscript page from the inaugural edition, two copies of the rare July 4, 1855, edition, notebooks in which Whitman drafted his verse and a succession of frontispieces for “Leaves of Grass,” each depicting the bearded Uncle Walt casually posed in all his rumpled glory.

“Leaves of Grass” may have been an expanding tribute to the poem that is America (to paraphrase Whitman), a cultural touchstone that invoked the “body electric” of both the new nation and its component parts, but its rise to prominence in American letters wasn’t entirely serendipitous.

For Whitman, a shrewd marketer who trumpeted his book’s genius in anonymous reviews in various New York papers — “An American bard at last!” gushed one of these — was adept at placing it in influential hands, including those of Ralph Waldo Emerson, who lauded the work as “the most extraordinary piece of wit and wisdom that America has yet contributed,” and New York Ledger columnist Fanny Fern.

The nearly tactile sensuality of “Leaves of Grass,” now a literary mainstay as the steady flow of school groups loping through the exhibit earlier this week testifies to, was not without its controversy, however.

Emerson, one of the book’s most notable early champions, attempted unsuccessfully to dissuade Whitman from including two of the more sexually charged poetry groupings, “Children of Adam” and “Calamus,” in the 1860 edition. Later the Boston district attorney threatened prosecution on obscenity charges if Whitman’s publisher continued to distribute the 1881-1882 edition with certain offending passages. Of course, the controversy only boosted sales when a Philadelphia publisher chose to go ahead with the printing.

Aside from “Leaves of Grass,” the exhibit explores a variety of Whitman’s endeavors, poetic and otherwise. Included here is a libretto Whitman penned for Rossini’s “La Gazza Ladra” (The Thieving Magpie), a ticket to one of his well-received lectures on Abraham Lincoln, and his pamphlets dissecting American democracy. Also featured is his Civil War-time poetry collection “Drum-Taps,” the second edition of which included the two cardinal Lincoln elegies, “When Lilacs Last in the Dooryard Bloomed” and “O Captain! My Captain!” (Both were also added to later editions of “Leaves of Grass.”)

The exhibit briefly touches on Whitman’s alleged homosexuality, mentioning his affection for, in the exhibit’s words, “a handsome farm boy from New York state” met in the course of his Civil War hospital visits; the poet’s confessions in a notebook of his “undignified pursuit” of the ex-confederate soldier and streetcar conductor Peter Doyle, which the exhibit points to as the best proof of his homosexuality; and his relationship with the teenage son of a family with whom he was close.

Whitman acolytes will appreciate the trove of personal effects on display, including a fountain pen, walking stick, eyeglasses, a lock of hair and even the cardboard butterfly the poet apparently posed on his hand in one photograph, then presented as evidence of his credentials as a true communer with nature.

In his later years, Whitman developed a sizable cult of personality. Oscar Wilde flocked to pay him homage. Caretakers catered to his needs, and scribes hung on his every word — Boswell style — down to his dying breath.

From his bedroom perch in Camden, N.J., overflowing with manuscripts (a water-stained photo of Whitman surrounded by a riot of papers is not to be missed), the ailing Whitman, who suffered a series of strokes beginning in 1873, designed his burial vault, modeled after William Blake’s engraving of “Death’s Door,” and penned his final poem, “A Thought of Columbus.”

Ten days later, the “old man, beautiful as the mist,” as poet Federico Garcia Lorca wrote of Whitman, had died — but not his spirit, as the final display case in the exhibit notes.

Like many other literary stars, Whitman lives on — both as artistic inspiration and advertising gimmick. The work of various artists from dancer Isadora Duncan to composer Charles Ives has been influenced by his legacy, and his name has been branded on everything from truck stops to shopping malls to think tanks — not to mention, at one time, his very own brand of “guaranteed Cuban” Walt Whitman cigars. Talk about an honor.

“Revising Himself” runs through Dec. 3 in the Southwest Gallery of the Library’s Jefferson Building. It is on view from 10 a.m. to 5 p.m. Monday through Saturday.