Like its 2006 predecessor, “African American Lives 2” craftily wields the bright shining beacon of celebrity to illuminate a chapter in the American national story that many of us tend to leave buried in history’s sub-basement. Through the course of four hour-long shows airing on PBS on the next two Wednesdays, Maya Angelou, Chris Rock, Jackie Joyner-Kersee, Don Cheadle, Tina Turner, Morgan Freeman, and a half-dozen others (including the show’s host and coproducer, a Harvard professor, Henry Louis Gates Jr.) work with genealogical experts to sort fact from fiction regarding the years before and after the family trees that took root in Africa were brutally uprooted and replanted in the New World by the slave trade.

“African American Lives 2” is a showcase of intimate one-on-one interviews between Mr. Gates and his celebrity participants. Together, they go through personalized scrapbooks of documents and photographs unearthed and assembled by a staff of researchers. Prompted by Mr. Gates, the guests gasp and shed tears of pride and pain at the triumphs and tragedies revealed with each turn of the page. Having done his own research, Mr. Gates already knows where and what each dramatic discovery will be, and he gently moves things along from disclosure to irony to historical riddle like a more articulate, academic, and partisan version of Ralph Edwards on the old “This is Your Life” program.

In episode one, “The Road Home,” syndicated talk radio host Tom Joyner learns of an appalling, racially motivated mass execution that decimated his family and drove them from Alabama in the early 20th century. Author Bliss Broyard recounts the discovery that her father, a New York Times literary critic, Anatole Broyard, was a black man who chose to “pass” as white. (The elder Broyard was profiled by Mr. Gates in his 1997 book “Thirteen Ways of Looking at a Black Man.”) Like much of what is discussed on “African American Lives 2,” Ms. Broyard’s story and the other participants’ responses indicate just how little is merely black or white about the issues at hand.

The second installment, “A Way Out of No Way,” recounts the saga of comedian Chris Rock’s maternal great-great-greatgrandfather, a Civil War veteran who was twice elected to the South Carolina State Legislature, only to be forced into sharecropping poverty when Reconstruction ended. Tina Turner discovers that the grade school she attended was built on land deeded by a prosperous ancestor for that purpose. Actor Don Cheadle learns that his forebears were enslaved by Native American Chickasaws and therefore weren’t covered by the Emancipation Proclamation. It wasn’t until well after the Civil War that his kin were “free at last, for real,” Mr. Cheadle says, hushed by the irony.

Because black African captives were considered property and therefore recorded through various bills of sale, wills, “slave schedule” census inventories, and other legal documents, “African American Lives 2” takes full advantage of the fact that “the genealogy of slavery” can be brought into sharp focus with the undertaking of archival scholarship. Moreover, no two ancestors’ ordeals were the same. The relationship between slave and owner was “much more nuanced,” Professor Gates says, than has been portrayed in popular culture.

When the paper trail ends, geneticists take up the hunt. The results of DNA research help to clarify each participant’s specific geographical connection to the African continent. DNA testing not only re-establishes family lines severed in the Middle Passage, it exposes the reality that, for most African-Americans, “not all of our roots lead to Africa.” Confronted by the scientifically confirmed truth that she has more Caucasian ancestry than the more historically flattering Native American influence she was brought up believing, Ms. Turner gracefully accepts, as her host points out, that “you’re from the tribe of … Europe!” Similarly, Mr. Rock laughs off his hitherto undocumented distant mixed heritage as the explanation for why “my jump shot is horrible!”

Though the show’s presentation occasionally lapses into crowd-pleasing facileness, there is nevertheless a plurality of amazingly articulate voices (and in the case of the theologian Peter Gomes, a marvelous stentorian Massachusetts accent) and a rich variation of personalities so sensitive to cathartic pathos and open to liberating fact that at the close of the fourth hour one is left hungry for more. Who wouldn’t want to go through Morgan Freeman’s and Maya Angelou’s scrapbook with them, after all? Nevertheless, for every candid, curious, self-effacing, and philosophical contemporary voice contextualizing history in the present, there is a multitude of tormented voices from the past bearing witness to brute injustice at its most vile. At one point, we read a slave ship captain’s itemized and notated list of those who died en route. Among the deaths by “apoplexy” and other illnesses, the slaver owner’s skipper describes in heartbreakingly concise detail the ordeal of a man who starved himself to death before landfall in the Chesapeake Bay rather than live in chains.

Whether descended from exploiter, exploited, or those who have arrived since, “African American Lives 2” is a compelling reminder that slavery’s legacy is a part of every American’s personal history. “Ultimately, we all went through it,” Professor Gates offers, “and we all had to survive it.”