The Federal Civil Defense Administration (FCDA) was organized by President Harry S. Truman on 1 December 1950 through Executive Order 10186, and became an official government agency via the Federal Civil Defense Act of 1950 on 12 January 1951. In 1958 the FCDA was superseded by the Office of Civil and Defense Mobilization when President Dwight D. Eisenhower merged the FCDA with the Office of Defense Mobilization. In its early years, the agency focused on evacuation as a strategy. The FCDA was first headed by Millard Caldwell under Truman, then Val Peterson (under Eisenhower).