Every spring, when the Tribeca Film Festival juggernaut cranks into motion, mention is dutifully made of its origins in the aftermath of the terrorist attacks of September 11, 2001. This year, that routine nod to the past is amply matched by a striking wave of historically minded selections in the documentary field. While the usual bounty of nonfiction films yielded a glut of artist biographies and foreign policy statements in 2007, this year’s batch revisits political figures and events from prior generations, and the films are often not shy about tweaking history accordingly.

Appropriately for the current Democratic presidential primary, a strain of nostalgia for progressive and liberal heroes of all stripes is on display at Tribeca. The epitome might be “A President to Remember: In the Company of John F. Kennedy,” by the cinema vérité pioneer Robert Drew. The generation-defining Democratic avatar is reintroduced through footage shot during the 1960 presidential primaries and Kennedy’s subsequent presidency, some of it lifted wholesale from Mr. Drew’s documentaries from the period — “Primary” and “Crisis.”

Such interest dovetails with the recent swing of the political pendulum, but other filmmakers at Tribeca follow the swing far beyond Washington, into all manner of cultural history. “Theater of War,” directed by John Walter (“How to Draw a Bunny”), delves into the Public Theater’s 2006 production of “Mother Courage” in order to re-examine Bertolt Brecht. Gabriel Figueroa Flores and Diego López Rivera’s “A Portrait of Diego: The Revolutionary Gaze” treats the radical Mexican painter Diego Rivera, while Paula Gaitán’s “Days in Sintra” remembers the fiery Brazilian director and Cinema Novo leader Glauber Rocha. Luis Lopez and Trisha Ziff’s “Chevolution” laments the mass production of Che Guevera’s famous black-and-white visage.

Even more crowded with would-be resurrected heroes is the quiet riot of “Profit motive and the whispering wind,” by John Gianvito. Having already amassed considerable buzz at international festivals, this fascinating travelogue simply documents the oft-forgotten memorials and graves of quashed freethinkers, rebellious slaves, labor leaders, and others, ranging from Thomas Paine to Susan B. Anthony to Paul Robeson. Deeply in touch with the aural and arboreal landscape of each site, Mr. Gianvito’s contemplative piece audaciously sets out a secret history.

Other countries also come under scrutiny in this festival edition’s tendency toward unearthing the past. The French-Algerian director Jean-Pierre Lledo seeks to counteract the “official” versions of Algerian independence from France, before and after, in “Algeria, Unspoken Stories.” Elsewhere, in “Two Mothers,” the fearless German filmmaker Rosa von Praunheim grapples with the Nazi legacy upon discovering he was adopted.

More recent nation-building turmoil comes alive in Michael Christoffersen’s “Milosevic on Trial,” about the slippery Serbian dictator’s tribunal before the International Criminal Court at the Hague. (For less weighty but no less passionate history, see Guy Maddin’s “My Winnipeg,” the irrepressible director’s “docu-fantasia” of self and city.)

Not a documentary but worth mentioning for its painful grounding in repressed facts is “Katyn,” from Andrzej Wajda, the great Polish filmmaker and, in a sense, cinematic historian. The director of the essential World War II chronicles “Kanal” and “Ashes and Diamonds” finally tackles the Katyn massacre, the 1940 mass murder of more than 27,000 Polish officers ordered by Stalin and covered up through the perestroika era. After detailing the fear and loathing of the postwar chill, Mr. Wajda’s film eventually doubles back for a head-on depiction of the assembly-line killing.

It’s sobering to think of such a trauma remaining off-limits for public discussion, which brings us to the trenchant meta-historical commentary of “Secrecy,” which was co-directed by Peter Galison and Robb Moss. The documentary probes the legal, political, and psychological aspects of the American government’s practice of classifying information, and traces it back to World War II. While presenting arguments for and against tight control, the film gradually becomes something more unnerving than an exposé, screed, or “white paper” summation — “Secrecy” describes a metastasizing mentality that can undermine both its own goals and responsible democracy.

Viewed in the context of the larger slate of nonfiction films at Tribeca, “Secrecy” speaks to the fragility of the information in all these other documentaries. So don’t be deceived by the bright lights of a festival bookended by such blockbusters-in-training as “Baby Mama” and “Speed Racer.” There’s plenty to chew on, learn from, and argue about in the shadows of the past investigated by this year’s documentaries.