German-Americans represent the largest self-declared ancestry group in the United States of America. The period from the 200th anniversary celebration of Germantown’s founding in 1883 to the end of the First World War was an age of intense turmoil within the ranks of German-American communities. These decades were marked by a massive political and cultural realignment as well as major contributions to the (self-)definition of German-Americanness. Historians and sociolinguists with backgrounds in German or American studies offer a fresh look at a critical period in the history of German-American communities.