This dissertation is a study of the creative writing workshop as a shaping institution of American poetry in the twentieth century. It takes as its starting point the observation that in the postwar period the rise of academic creative writing programs introduced profound material changes into the lives of American poets, as poetry became professionalized within the larger institution of the university. It goes on to argue that poets responded to these changes in ways that are directly legible in their work, producing a variety of poetic interrogations of the cultural and psychological effects of the reflexive professional self-fashioning that became, partially through the workshop, the condition of modern literary life. In other words, as poets became students and teachers, their classroom and career experiences occasioned new kinds of explorations of identity, performance, vocation, authority, and the cultural status of poets and poetry. The cluster of concerns linked to the evolving institution of "creative writing" shows stylistically diverse works to be united, and also resonates with and helps to clarify the major debates within the poetry world over the past decades between the camps of the "mainstream" and the "avant-garde" or, as Robert Lowell put it in 1959, "the cooked and the raw." My dissertation examines a variety of iterations of the relationship between workshop culture and poetic production through case studies of the poets Robert Lowell, Sylvia Plath, Anne Sexton, Theodore Roethke, Richard Hugo, and Jorie Graham.