For Republican Sen. John McCain (Ariz.), whose father, grandfather and two great uncles are buried in the nation’s most sacred cemetery, hosting a documentary on the subject was — it seems — the natural thing to do.

As McCain notes in the Travel Channel’s upcoming feature on Arlington National Cemetery, the 600-plus-acre tract just west of the Capitol across the Potomac River is “what I consider the most hallowed ground in the country.”

The 48-minute film, which airs at 9 p.m. May 12 on the Travel Channel, traces the evolution of the graveyard from its origins as something of a “pauper’s cemetery” for unclaimed or impoverished Civil War dead to its current status as the preferred ending point of political leaders and military heroes.

Its provenance as a dumping ground for Civil War fallen was undertaken partly in spite by Union Brig. Gen. Montgomery C. Meigs against Confederate Gen. Robert E. Lee, who had lived on the Arlington estate with his wife, Mary Anna — a descendent of the adopted son of President George Washington. Meigs, according to the documentary, felt his former colleague Lee had betrayed him by taking up arms against the Union and vowed to ensure the Lees would never return by burying bodies right up to the edge of Arlington House and turning its rose garden into one of the largest mass graves — of skulls, legs and arms — in the nation.

Of course over the years, the cemetery grew in stature. As McCain notes, today “the who’s who of Arlington reads like a portrait of American history.” Its varied inhabitants range from Union Gen. Abner Doubleday, mythic inventor of baseball, to World War II veteran and boxing great Joe Louis and North Pole explorer Matthew Henson.

One of the gems of the documentary is its insight into how President John F. Kennedy’s eventual burial in the cemetery — an event which caused requests for interment there to skyrocket by 400 percent — transpired. As former Arlington National Cemetery tour guide Paul Fuqua recounts, Kennedy had visited the very spot where the eternal flame marking his grave now burns during a 1963 visit to Arlington House — a moment which eerily foreshadowed his assassination. Looking out at the view across the Arlington Memorial Bridge to the Lincoln Memorial, Kennedy is said to have remarked, “This is so beautiful … so wonderful. I could just stay here forever.”

Seven months later, just after Kennedy’s premature death, Robert Kennedy returned with Secretary of Defense Robert McNamara and inquired of Fuqua, “Would you mind coming out and showing us where you were when you spoke to my brother?” — a question which led to the selection of that location for Kennedy’s gravesite, lit by an eternal flame similar to the one found at Paris’ Tomb of the Unknown Soldier, as was Jackie Kennedy’s wish.

The documentary also underscores the continuity of tradition, as maintained by members of the 3rd U.S. Infantry Regiment or The Old Guard, as they are known. Their exhaustive daily preparations are detailed down to the cleaning of the dirt from the crevice of their visors to the burning of frayed threads on their jacket lapels. Of course, the Old Guard’s most prominent duty — guarding the Tomb of the Unknowns — also gets plenty of attention. Since its inception after World War I — when Congress first called for the burial of one unknown soldier for Americans to honor from the war — the tomb has held representatives from all major conflicts through Vietnam, until 1998 when Air Force Lt. Michael Blassie was positively identified as the remains of the combatant from Vietnam. The advent of DNA testing and mandatory DNA records, the film notes, has mitigated the likelihood of future anonymous casualties.

Arlington’s proximity to the United States’ most recent national tragedy — “so close actual remnants of the explosion landed” in the cemetery — catapults the landmark into a contemporary context. Sixty-six individuals who died in the Sept. 11, 2001, attack on the Pentagon are also buried there, according to the film, and several members of The Old Guard participated in search and rescue missions at the Pentagon following the attacks. In an appropriately elegiac gesture, 49 of the 66 were laid to rest on the far edge of the cemetery in full view of the “scarred Pentagon” — their sobering presence, adding yet another page, as McCain has said of all those who are buried at Arlington, “in the biography of America.”