R. P. Blackmur was an American critic and poet, as well as a professor of English literature and creative writing at Princeton University. At the time of his death, he had completed five books and numerous plays, poems, and short stories. He devoted most of his life to studies on Henry Adams - someone he saw in himself. In his lifetime, he received a share of adulation, but he was not successful in the way that success is commonly measured. In this work, Russell Fraser follows the course of Blackmur's self-declared failed genius. He tells the story of his precocious youth in Cambridge; his eclectic education; his years of poverty and renown as a poet, novelist, freelance music critic, and essayist; his obsessive marriage to artist Helen Dickson; his entangled friendships with T. S. Eliot, Delmore Schwartz, Allen Tate, and John Berryman; and, his passion for the wilds of Maine. He discusses Blackmur's crucial role in the literary magazines of the twenties and thirties; his unique influence as instructor of creative writing; the emotional and professional price he paid for a doubtful security at Princeton University; and, the torment of wavering between intellectual inertia and prolific inspiration. With empathy and insight, Fraser shows how the trajectory of Blackmur's career parallels the movements in the American literary scene; the experiments in poetry and fiction; the development of the New Criticism; the writer's conflict between order and anarchy, taxonomy and the full response; and, the emergence of the critic as artist. A biography, intellectual history, and literary criticism, "A Mingled Yarn" unravels Blackmur's complex character and celebrates his great achievement.