2 U.S. Code § 6 - Reduction of representation
Should any State deny or abridge the right of any of the male inhabitants thereof, being twenty-one years of age, and citizens of the United States, to vote at any election named in the amendment to the Constitution, article 14, section 2, except for participation in the rebellion or other crime, the number of Representatives apportioned to such State shall be reduced in the proportion which the number of such male citizens shall have to the whole number of male citizens twenty-one years of age in such State.
Source(R.S. § 22.)
R.S. § 22 derived from act Feb. 2, 1872, ch. 11, § 6,17 Stat. 29.