Shannon Brennan, the late Marine's sister who lives in Charlottesville, Va., says Arlington is special because "you connect with other families here. We all need some time for quiet reflection."

Arlington National Cemetery has been a place of quiet reflection for almost 150 years. It now has nearly 4 million visitors annually and 300,000 "residents," as Poole calls them. "And every last one of them has a story."

Poole's book tells the stories of many of those buried in 70 sections across these rolling hills just across the Potomac from Washington, D.C. On Hallowed Ground is part history lesson, part tourist guide, part mystery novel.

And though it was a four-year project, Poole says his book "just scratches the surface" from the cemetery's Civil War beginnings in the 1860s to today's tourist must-see, the Changing of the Guard.

As is tradition on Veterans Day, President Obama is expected to lay a wreath this morning on the Tomb of the Unknown Soldier.

The solemnity of today's ceremony is a far cry from the political maneuverings of the cemetery's early years. To discourage the Custis-Lee family from returning to the family plantation that became the cemetery, for instance, Yankee officers were buried near Confederate Gen. Robert E. Lee's mansion, which still sits atop the cemetery grounds.

The rest is history. Rich history.

Two presidents are buried here John F. Kennedy and William Howard Taft along with eight Supreme Court justices and more than a handful of famous names: Abner Doubleday, Audie Murphy, Glenn Miller and boxer Joe Louis, to name just a few. Also buried on the grounds is Black Jack, the rambunctious "riderless" horse that took part in Kennedy's funeral procession after the president was assassinated in 1963.

But Pierre L'Enfant has the best view, at the top of the hill in front of Lee's mansion, overlooking the capital city he helped design.