Rossiter allowed Draper two years to complete the entire project, the history of American communism from its origins in 1919 until the sacking of party leader Earl Browder at the end of World War II. Draper set to work, mustering sources and conducting interviews with living participants of the formative period of the American Communist Party. One of those with whom he conducted an extensive correspondence was James P. "Jim" Cannon, a midwesterner who was sacked from the organization in 1928 for supporting Leon Trotsky and the Russian "Left Opposition." Draper noted that Cannon's letters soon became "more formal, better organized, each a little gem of its kind." These letters of Jim Cannon to Ted Draper were ultimately published in book form as "The First Ten Years of American Communism" in 1962.