A Conversation: History Professor Chad L. Williams on Discovering W.E.B. Du Bois’s Lost Book on Black Americans and the First World War. When the United States declared war on Germany in 1917, the legendary American intellectual and activist W. E. B. Du Bois urged Black Americans to support the war effort and enlist in the military. He believed that full citizenship would become a reality for African Americans with a showing of patriotism and sacrifice in war.