In 1865 Walt Whitman was dismissed from his clerkship in the Department of the Interior because Secretary James Harlan judged Leaves of Grass indecent, unfit to be read aloud "by the evening lamp." Most eloquent among Whitman's defenders was William Douglas O'Connor, whose pamphlet The Good Gray Poet, a panegyric to Whitman and an attack on literary censorship in general and Harlan in particular, was the first of his many heroic if sometimes excessive efforts in Whitman's behalf. A gifted polemicist and a stout though not always judicious advocate of causes (he wrote several screeds favoring Bacon as the author of Shakespeare's works), O'Connor devoted much of his literary life to establishing Whitman and Leaves of Grass in the world of American letters. Whitman considered O'Connor his staunchest "literary believer and champion from the first and throughout . . . for twenty-five years," and indeed, despite a personal estrangement between the two men, O'Connor's support of Whitman the poet never wavered. O'Connor's own literary efforts may command little interest today, but his championship of Whitman as a great, original American poet rendered lasting service to literature. Appropriately, this study of his career is complemented by carefully annotated texts of six of his Whitman essays, including The Good Gray Poet. A complete O'Connor bibliography is also included.