Entitled: "American Red Cross serves humanity Join!" American Red Cross membership drive poster showing a Red Cross nurse holding a large red cross. During WWI, the American Red Cross faced an unprecedented national need for its service. Raising the funds to deliver this service required that the organization use advertising to appeal directly to the American people. Posters represented one of the most compelling and popular components of the campaign. More than eighteen thousand Red Cross nurses served with the Army and Navy Nurse Corps during WWI.