By the outbreak of World War I, some Americans were concerned about divided loyalties of German immigrants and their descendants. A nativist movement affected Omaha. The Federal government enforced the Alien and Sedition Acts against Germans nationals. Germans who were not American citizens were required to register with the Federal government as "Alien Enemies". Although Valentin Peter had earlier been a supporter of Germany against Great Britain, by the outbreak of the war, the editor of the "Omaha Tribüne" had become an ardent supporter of the United States' involvement in World War I on the side of Great Britain.