18 U.S.C. § 1
Section 1 · Repealed. Pub. L. 98473, title II, 218(a)(1), Oct. 12, 1984, 98 Stat. 2027]
Amended 1 time on record
Applied in 472 court decisions — leading case Duncan v. State of Louisiana (1968)
Most recently applied in United States v. Vazquez-Narvaez (April 2025)
Applied most in the Ninth Circuit Circuit (51 decisions)
Cases citing this section usually also cite 18 U.S.C. § 3401 · 18 U.S.C. § 371 · 21 U.S.C. § 841
How often courts cite this section
Court decisions citing this, by year.Markers show enactment, consequential amendments, and circuit splits over this section — watch for a citation surge after a change or a disagreement. The dip in the last several years is a data-coverage gap, not a real trend — our corpus holds fewer opinions from the most recent years, so recent citations are undercounted.
(a) "Classified information", as used in this Act, means any information or material that has been determined by the United States Government pursuant to an Executive order, statute, or regulation, to require protection against unauthorized disclosure for reasons of national security and any restricted data, as defined in paragraph r. of section 11 of the Atomic Energy Act of 1954 (42 U.S.C. 2014(y)).
(b) "National security", as used in this Act, means the national defense and foreign relations of the United States.