Final answer:
The 13th Amendment abolished slavery with the exception that forced labor could still be used as a punishment for those duly convicted of a crime.
Step-by-step explanation:
The 13th Amendment to the United States Constitution, passed in 1865, officially abolished slavery and involuntary servitude in the country. However, it included an exception clause stating that 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. Therefore, the individuals who were still allowed to be forced to work were people who were found guilty of a crime. This exception has led to the practice of convict leasing and, more broadly, to discussions about the implications of forced labor for incarcerated people.