Section, act Apr. 27, 1935, ch. 85, § 16, as added Feb. 29, 1936, ch. 104, § 1, 49 Stat. 1151; amended Aug. 7, 1956, ch. 1030, § 1, 70 Stat. 1115; Sept. 14, 1960, Pub. L. 86–793, § 1, 74 Stat. 1030; Mar. 22, 1961, Pub. L. 87–5, § 2, 75 Stat. 6; Aug. 8, 1961, Pub. L. 87–128, title I, § 132, title IV, § 401, 75 Stat. 302, 319; Mar. 30, 1962, Pub. L. 87–425, § 2, 76 Stat. 50; May 15, 1962, Pub. L. 87–451, § 4, 76 Stat. 70; Sept. 27, 1962, Pub. L. 87–703, title I, § 101(4), (5), title III, § 302, 76 Stat. 606, 607, 612; May 20, 1963, Pub. L. 88–26, § 3, 77 Stat. 45; Nov. 3, 1965, Pub. L. 89–321, title III, § 302, title VI, § 602(g), 79 Stat. 1190, 1208; Oct. 11, 1968, Pub. L. 90–559, § 1(1), 82 Stat. 996; Nov. 18, 1969, Pub. L. 91–118, §§ 1–3, 83 Stat. 194, 195; Nov. 30, 1970, Pub. L. 91–524, title VIII, § 801, 84 Stat. 1379; June 6, 1980, Pub. L. 96–263, § 1, 94 Stat. 438; Nov. 28, 1990, Pub. L. 101–624, title XIV, § 1455, 104 Stat. 3614; Nov. 2, 1994, Pub. L. 103–437, § 6(s), 108 Stat. 4587, related to limitation on obligations incurred for purpose of carrying out certain sections and Great Plains conservation program.