The title of Ava DuVernay's extraordinary and galvanizing documentary refers to the 13th Amendment to the Constitution, which granted freedom to enslaved people. Except, it didn’t really. The drafters of the amendment included a loophole that allowed for the re-enslavement of any person convicted of a crime. 13th explores The progression from that loophole to the horrors of mass criminalization and the sprawling American prison industry. With a potent mixture of archival footage and testimony from a dazzling array of activists, politicians, historians, and formerly incarcerated women and men, DuVernay creates a work of grand historical synthesis.