In the already woefully overlooked field of American radicalism, William Foster (the "Z." was a self-addition at the beginning of his career in the leftist press) is perhaps one of the most overlooked figures. Rising through the ranks of the Wobblies and the AFL, Foster eventually became a high-ranking member of the American Communist Party, replacing Earl Browder as party leader. Little is known of Foster's personal life, and in compensation Johanningsmeier provides much background and context on Foster's political evolution, including the balancing act he and other American Communists maintained between addressing local concerns and heeding the word of party leaders in the Soviet Union. Forging American Communism is a thoughtful life study that does much towards explaining why socialist and communist politics appealed so strongly to working-class radicals in the first half of the 20th century.