Thus there was something substantial to celebrate as attendees flocked to the after party at the Tavern on the Green, which was packed solid. Ava DuVernay, director of “The 13th,” was there, surrounded by photographers and those commending her for her impressive achievement in giving weight and depth to a subject that urgently needs exploration. With an array of historical film clips, interviews, commentary, graphs, professorial analysis, use of rap and savvy packaging, DuVernay stitched together a panoramic, intelligent and compelling portrait of the ramifications of racial discrimination in America that leaves a deep emotional impact.

The film traces the role of race from the beginning, with a Southern society’s economy built on slavery. The 13th Amendment to the U. S. Constitution, ratified and adopted in 1865, says: “Neither slavery nor involuntary servitude, except as punishment for crime whereof the party shall have been duly convicted, shall exist within the United States.” The documentary points out that after slavery was abolished, those trying to hold on to the system turned to convicting freed slaves of petty crimes, thereby enabling them to be imprisoned and forced to work as slave labor.

DuVernay brilliantly traces the historical road to demonstrate that the tactic has grown and still exists, as reflected in the ever-expanding prison population marked by comercialziation. Racism remains deeply imbedded. Under the war on crime that a succession of politicians have pursued, African-Americans have been labeled with criminality and given long sentences for minor drug violations to the point that the prisons are impossibly overcrowded. The film notes that America has the greatest percentage of prisoners in the world, and of these, a dramatically disproportionate are black, as statistics cited show. Once imprisoned, in many states voting rights are taken away permanently, and it becomes difficult to get a job because of the record, no matter how minor the offense.

The profit motive is still there, as turning over prisoner operations to private business has resulted in big profits and ever-worsening conditions driven by the incentive to make money off incarceration. One comes away from the film struck by how deeply unjust the prison system and sentencing procedures are, such as the whole three-strikes-and-you’re out policies.

We witness through clips and commentary the constant thread of racism running through our history, right up to the present with the explosion of anger over the number of African-Americans gunned down by police. The film covers brutal lynching in the past, illustrated by deeply upsetting photographs, moving also to the subject of currrent killings and the Black Lives Matter movement. The overwhelming point made is that racial discrimination has been and remains deeply rooted in the country’s DNA.

DuVerny presents clips of a series of U.S. presidents contributing to putting more blacks in prisons. We see Bill Clinton sounding off on the need to put criminals away for long sentences under the crime bill passed during his presidency. We see a past clip of Hillary Clinton also supporting such measures, with most of the incarcerated turning out to be the petty possessors and users of drugs, with blacks hooked on the cheaper crack cocaine as opposed to the more expensive drugs used by upscale whites.

In fairness, there is also a clip of Bill Clinton admitting that he was wrong in his approach. That’s admirable, but the damage was done. The prison population has soared so high that overcrowding has resulted in disastrously inhuman conditions.

What is especially effective about “The 13th” is the sharp way in which it is presented. Huge letters with key words emblazon the screen with rap lyrics underscoring the meaning. The editing of the vast amount of material packed into 100 minutes makes for super clarity.