Prior to renumbering of sections 501 to 543 of this chapter as sections 1501 to 1543 by Pub. L. 102–83, § 5(a), Aug. 6, 1991, 105 Stat. 406, section 531 of this chapter, Pub. L. 85–857, Sept. 2, 1958, 72 Stat. 1137; Pub. L. 90–77, title I, § 105, Aug. 31, 1967, 81 Stat. 179, which provided for a monthly pension to widows of Mexican War veterans, was repealed by Pub. L. 94–169, title I, § 101(2)(F), Dec. 23, 1975, 89 Stat. 1014, effective Jan. 1, 1976.