The return of peace in 1918 brought with it problems that would persist into the 1920s. Government efforts to suppress opposition to U.S. involvement in World War I fostered an atmosphere of fear and repression that continued after the war. An influenza epidemic that killed hundreds of thousands of Americans and millions of people around the world heightened the climate of anxiety. Finally, the abrupt transition away from a wartime economy produced inflation, labor unrest, and escalating racial tensions.