In June 1939 Congress assigned to the Secretary of the Interior and the Army and Navy Munitions Board the task of determining which materials are strategic and critical to American defense, and provided for acquisition of stocks of these materials.[265] Congress also encouraged the development of mineral resources within the United States. Two months later Congress approved the exchange of surplus agricultural commodities held by the Commodity Credit Corporation for stocks of strategic and critical materials produced abroad.[266] Under the fiscal 1941 Appropriations Act, the Navy Department obtained funds for procurement of strategic and critical materials in accordance with the Act of June 7, 1939.[267] In this statute, and in a July 1940 Act to expedite the strengthening of the national defense, the President also was authorized to expend large sums on acquisition of such materials.[268] The Defense Production Act of 1950 empowers the President to make provision either for purchases of, or commitments to purchase metals and other raw materials, including liquid fuels. The government may use the acquired items or offer them for resale. The same Act also empowers the President to encourage the exploration, development, and mining of critical and strategic minerals and metals.[269] The Mutual Security Act of 1951 also provides sustenance for the stockpiling program. The Director for Mutual Security is authorized to initiate projects designed to increase production and help in obtaining raw materials in which deficiencies exist among the United States’ free world allies. The purpose of aiding recipients of American aid to develop their own stockpiling program of critical materials is to reduce the steady drain on United States resources.[270] The power of condemnation was added to the power of requisitioning granted in the 1950 Defense Production Act when Congress in a 1951 amendment empowered the President in the interest of national defense, and when deemed necessary by him, to acquire materials needed by the government. Acquisition may be by transfer, donation, purchase, or, if needed, properly instituted judicial proceedings.[271]