Classical composers seeking to create an American sound enjoyed unprecedented success during the 1930s and 1940s. Aaron Copland, Roy Harris, Howard Hanson, and others brought national and international attention to American composers for the first time in history. In the years after World War II, however, something changed. The prestige of musical Americanism waned rapidly as anti-Communists made accusations against leading Americanist composers. Meanwhile, a method of harmonic organization that some considered more Cold War, appropriate, serialism, began to rise in status. For many composers and historians, the Cold War had effectively 'killed off' musical Americanism. In this work, the author offers a fuller, more nuanced picture of the effect of the Cold War on Americanist composers.