In the United States, the 13th Amendment to the United States Constitution prohibits slavery and involuntary servitude except as a punishment for a crime of which one has been convicted. In the latter 2010s, a movement has emerged to repeal the exception clause from both the federal and state constitutions.
List of amendments
Federal
Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction. Amendment XIII, Section 1.
State
With exceptions
Arkansas: There shall be no slavery in this State, nor involuntary servitude, except as a punishment for crime. No standing army shall be kept in time of peace; the military shall, at all times, be in strict subordination to the civil power; and no soldier shall be quartered in any house, or on any premises, without the consent of the owner, in time of peace; nor in time of war, except in a manner prescribed by law. Arkansas Constitution, Article 2, Section 25. California: Slavery is prohibited. Involuntary servitude is prohibited, except to punish crime. Article I, Section 6. Georgia: There shall be no involuntary servitude within the State of Georgia except as a punishment for crime after legal conviction thereof or for contempt of court. Article I, Section 1 Paragraph XXII. Indiana: There shall be neither slavery, nor involuntary servitude, within the State, otherwise than for the punishment of crimes, whereof the party shall have been duly convicted. Article 1, Section 37 Iowa: There shall be no slavery in this State; nor shall there be involuntary servitude, unless for the punishment of crime. Article I, Section 23 Kansas: There shall be no slavery in this state; and no involuntary servitude, except for the punishment of crime, whereof the party shall have been duly convicted. Kentucky: Slavery and involuntary servitude in this state are forbidden, except as a punishment of crimes, whereof the party shall have been duly convicted. Article I, Section 25 Louisiana: No person shall be denied the equal protection of the laws. No law shall discriminate against a person because of race or religious ideas, beliefs, or affiliations. No law shall arbitrarily, capriciously, or unreasonably discriminate against a person because of birth, age, sex, culture, physical condition, or political ideas or affiliations. Slavery and involuntary servitude are prohibited, except in the latter case as punishment for crime. Article I, Section 3. Michigan: Neither slavery nor involuntary servitude, unless for the punishment of crimes, shall ever be tolerated in this State. Article I, Section 9. Minnesota: No member of this state shall be disfranchised or deprived of any of the rights or privileges secured to any citizen thereof, unless by the law of the land or the judgement of his peers. There shall be neither slavery nor involuntary servitude in the state, otherwise than as punishment for a crime of which the party has been convicted. Article I, Section 2 Mississippi: There shall be neither slavery nor involuntary servitude in this State, otherwise than in the punishment of crime, whereof the party shall have been duly convicted. Article 3, Section 15 Nevada: Neither slavery nor involuntary servitude, unless for the punishment of crimes, shall ever be tolerated in this State. Article 1, Section 17. North Carolina - Article 1 Section 17: Slavery is forever prohibited. Involuntary servitude, except as a punishment for crime whereof the parties have been adjudged guilty, is forever prohibited. North Dakota: Neither slavery nor involuntary servitude, unless for the punishment of crimes, shall ever be tolerated in this State. Article 1, Section 17 Ohio: There shall be no slavery in this state; nor involuntary servitude, unless for the punishment of crime. Article I, Section 6. Wisconsin: There shall be neither slavery, nor involuntary servitude in this state, otherwise than for the punishment of crime, of which the party shall have been duly convicted. Article I