Little-known parts of Mississippi’s civil rights history will be told in the PBS documentary, “American Reckoning.”

The show airs at 9 p.m. central standard time on Tuesday, Feb. 15, on PBS.

It explores a federal cold case investigation of the murder of Wharlest Jackson Sr., who was the treasurer of the Natchez branch of the National Association for the Advancement of Colored People until his assassination by a car bomb.

Rare film footage — much of it never before broadcast on national television — taken in Natchez more than 50 years ago, will shine the spotlight on one of the still-unresolved killings from the civil rights era.

Compared to the deaths of Emmett Till and Medgar Evers, the bombing death of NAACP leader Wharlest Jackson has received little attention outside of Natchez.

“American Reckoning,” created by directors and producers Brad Lichtenstein and Yoruba Richen, will examine black opposition to racist violence in Mississippi as it focuses on efforts to bring to justice those responsible for Jackson’s death, according to an announcement of the film written by Anne Husted, Series Publicity Manager for FRONTLINE.

The documentary will use film footage from Natchez during the civil rights era, much of it never-before broadcast. Made available through the Amistad Research Center in New Orleans, the footage was taken by Ed Pincus and David Neuman for 10 weeks in 1965 when Pincus and Neuman were documenting early efforts to organize and register Black voters.

“American Reckoning offers a window into an untold story of a Black-led liberation and self-defense movement in Natchez, as well as the funeral of Wharlest Jackson Sr. and its aftermath,” Husted wrote.

In addition to film footage from 1965 and 1967, interviews and archival material from that time, the documentary will also take a look at the reporting of Concordia Sentinel journalist Stanley Nelson, who investigated allegations of the involvement of a Ku Klux Klan offshoot, known as the Silver Dollar Group, in Jackson’s murder.