§ 2241. Aggravated sexual abuse
(a) By Force or Threat.— Whoever, in the special maritime and territorial jurisdiction of the United States or in a Federal prison, or in any prison, institution, or facility in which persons are held in custody by direction of or pursuant to a contract or agreement with the head of any Federal department or agency, knowingly causes another person to engage in a sexual act—
(1) by using force against that other person; or
(2) by threatening or placing that other person in fear that any person will be subjected to death, serious bodily injury, or kidnapping;
or attempts to do so, shall be fined under this title, imprisoned for any term of years or life, or both.
(b) By Other Means.— Whoever, in the special maritime and territorial jurisdiction of the United States or in a Federal prison, or in any prison, institution, or facility in which persons are held in custody by direction of or pursuant to a contract or agreement with the head of any Federal department or agency, knowingly—
(1) renders another person unconscious and thereby engages in a sexual act with that other person; or
(2) administers to another person by force or threat of force, or without the knowledge or permission of that person, a drug, intoxicant, or other similar substance and thereby—
(A) substantially impairs the ability of that other person to appraise or control conduct; and
(B) engages in a sexual act with that other person;
or attempts to do so, shall be fined under this title, imprisoned for any term of years or life, or both.
http://www.law.cornell.edu/uscode/us...I_20_109A.html
More history:
http://www.musc.edu/vawprevention/research/sa.shtml