The Communist Party of the United States of America was founded amid the wave of international revolutionary struggles inspired by the Russian Revolution, with the express goal of leading US workers in the struggle against capitalism. Despite these intentions, the first years of its existence were plagued by sectarianism, infighting, and an obsession over the need for an underground organization. It was only through the intervention of the Communist International (Comintern) that the party was pushed to “Americanize,” come out from “the underground,” and focus on the struggles for Black liberation. This unique contribution documents the positive contribution of the Comintern in its early revolutionary years and its decline under Stalin.