Accented America is a sweeping study of U.S. literature between 1890-1950 that reveals a long history of English-Only nationalism: the political claim that U.S. citizens must speak a nationally distinctive form of English. This perspective presents U.S. literary works written between the 1890s and 1940s as playfully, painfully, and ambivalently engaged with language politics, thereby rewiring both narrative form and national identity. The United States has always been a densely polyglot nation, but efforts to prove the existence of a nationally specific form of English turn out to be a development of particular importance to interwar modernism. If the concept of a singular, coherent, and autonomous 'American language' seemed merely provocative or ironic in 1919 when H.L. Mencken emblazoned the phrase on his philological study, within a short period of time it would come to seem simultaneously obvious and impossible. Considering the continuing presence of fierce public debates over U.S. English and domestic multilingualisms demonstrates the symbolic and material implications of such debates in naturalization and citizenship law, presidential rhetoric, academic language studies, and the artistic renderings of novelists. Against the backdrop of the period's massive demographic changes, Accented America brings a broadly multi-ethnic set of writers into conversation, including Gertrude Stein, Jean Toomer, Henry Roth, Nella Larsen, John Dos Passos, Lionel Trilling, Americo Paredes, and Carlos Bulosan. These authors shared an acute sense of linguistic standardization during the interwar era and contend with the defamiliarizing sway of radical experimentation with invented and improper literary vernaculars. Mixing languages, these authors spurn expectations for phonological exactitude to develop multilingual literary aesthetics. Rather than confirming the powerfully seductive subtext of monolingualism-that those who speak alike are ethically and politically likeminded-multilingual modernists composed interwar novels that were characteristically American because, not in spite, of their synthetic syntaxes and enduring strangeness.