American Red Cross in Great Britain, circa 1918. One unit of the famous "Flying Squadron" priding themselves on being able to get under way within three minutes of the time a call is received. The most important volunteer group in America during WWI was the American Red Cross. The Red Cross was still a very small organization and not yet a very well known group in the United States when World War I broke out in Europe (1914). During WWI more than eighteen thousand Red Cross nurses served with the Army and Navy Nurse Corps. Some of these nurses worked at American base hospitals, at field units, and aboard ships, whereas others, served at home combating the 1918 influenza epidemic and providing medical services to military camps, munitions plants, and shipyards. They also played an important role in coordinating volunteer efforts. One of these was a nationwide knitting campaign to produce woolen socks and other warm weather clothing. The Red Cross helped to recruit ad train ambulance drivers and orderlies at various universities. There was also a youth effort. By the time the war ended in November 1918, the Red Cross had become a major national humanitarian organization.