US involvement in World War I lasted from April 6, 1917 until the war's end on November 11, 1918. During this time, approximately 200,000 Latino Americans fought for the United States. The majority of these Latino servicemen were Mexican Americans. Many of these men experienced discrimination in the service, and some went so far as to hide their Mexican ancestry to avoid prejudicial treatment. Unlike African American servicemen, however, Mexican Americans did not serve in segregated units during WWI. Even as white servicemen harassed the Mexican American soldiers for their "barrio English," Mexican American soldiers proved decisive in several key skirmishes, including the Battle of Saint-Mihiel and the Meuse–Argonne offensive.