Civil Defense was referred to as ‘civilian defense’ when first coined in the U.S. just prior to The Great War - World War I. Owing mostly to the fact that United States soil had yet to be attacked during the 20th century, it was the attack and sinking of The Lusitania in 1915 by an early German U-Boat that sparked interest in a system of civilian defense modeled after Great Britain’s. The resulting Council of National Defense, inaugurated on August 29, 1916 convened for the remainder of World War I. Though suspended until a year prior to the attack on Pearl Harbor, much of the infrastructure from the earlier organzation remained. President Roosevelt reorganized the Council into The Office of Civilian Defense (OCD) on May 20, 1940. The OCD was first headed up by Fiorello La Guardia, Mayor of New York City. It’s initial charter was to promote protective measures and elevate national morale. These efforts expanded into a network of local and national groups working together to mobilize the civilian population in response both internal and external threats. At it’s zenith during World War II, the Civil Defense Corps comprised as many as 10 million American volunteers and paid employees.