I sadly can’t say that I’ve kept fully abreast of Henry G. Sanders’ acting career, since his star-turn in Charles Burnett’s 1979 magnum opus Killer Of Sheep; But, a glance at his IMDB resume informs me that he’s certainly been busy over the the years, albeit in what would be described as *bit* parts in TV and film projects – small screen classics like Hill Street Blues, Diff’rent Strokes, Murder, She Wrote, Miami Vice, Cagney & Lacey, Matlock, L.A. Law, and Grey’s Anatomy, most recently, and on the big screen in Bull Durham, the American remake of Jean-Luc Godard’s Breathless, and, just last year, the Jackie Robinson bio 42. He often played unnamed stock characters like cops (or some other form of security personnel), judges, mailmen and ministers. In some cases, his parts are listed as “uncredited.” 

His longest and most prominent stint on a TV series was playing a character named Robert E. (a former slave who comes to the frontier town of Colorado Springs to start over as a blacksmith) for 6 seasons on CBS’s early 1990s period western drama Dr. Quinn, Medicine Woman.

Now the 71-year-old Sanders, who, by the way, served in the Army, where his two tours of duty in Vietnam earned him a Purple Heart, and who once said that he never intended to be an actor (“I kind of fell into it” he shared in a 1996 interview), has been cast in Ava DuVernay’s upcoming MLK drama Selma, playing Cager Lee, Jimmie Lee Jackson’s grandfather. 

To be portrayed by the previously-cast Keith Stanfield, Jimmy Lee Jackson was a civil rights protestor shot and killed by Alabama State Troopers in 1965, during a march that was violently broken up by law enforcement – a moment that helped inspire the Selma to Montgomery marches. 

Jackson’s death happened while he was trying to defend his mother (Viola Jackson) and grandfather (Cager Lee) – who were also part of the protest march – from beatings with clubs by white state troopers in Marion, Alabama.

It would take another 45 years before Jackson’s killer, James Bonard Fowler, would be brought to justice. Although his prison sentence was laughable. In 2010, the then 77-year-old Fowler was sentenced to six months in jail in his home county.

Photos of Cager Lee Sr (he named his son Cager Lee) aren’t exactly in abundance online; The best I could do is the above black & white photo (next to Henry G. Sanders) taken during Jimmy Lee Jackson’s funeral in Selma, AL, on March 3, 1965. Seated far right are grandfather, Cager Lee Sr, who was 82 years old at the time, and mother, Viola Jackson.

Sanders joins David Oyelowo as Martin Luther King Jr.Carmen Ejogo as Coretta Scott King, Tom Wilkinson as President Lyndon B. Johnson, Ledisi as Mahalia Jackson, and Keith Stanfield as Jimmie Lee Jackson in a film produced by Oprah WinfreyBrad Pitt’s Plan B and Christian Colson (who won an Oscar for producing Slumdog Millionaire). 
Paramount Pictures is also on board the Pathe UK-backed project, which centers on the 1965 landmark voting rights campaign regarded as the peak of the civil rights movement.
By the way, Henry G. Sanders also stepped behind the camera once, to direct a short film in 2009, titled Carla, about an Iraq war veteran battling PTSD. He also penned the screenplay for it.
And if you haven’t seen Killer of Sheep, what’re you waiting for? It’s on DVD.