Answering the call : the U.S. Army Nurse Corps, 1917-1919 : a commemorative tribute to military nursing in World War IOnly seventeen years after the establishment of the Army Nurse Corps (ANC) , America entered into a global conflict known as World War I. It was a short period, less than two years until the Armistice in 1918, but the demands on nurses were profound. The ANC grew from 403 members to over 22,000 utilizing a significant portion of all the professional nurses in the United States.