From time to time, I get e-mails from white readers railing against my "unhealthy race obsession."

Which includes any reference to slavery, even a passing one.

That baffles me. Because, of all places, Philadelphia may be the least likely room to hide the elephant of bondage.

Here we are, living in a historically rich region where founding fathers doubled as slave owners; where former slaves joined forces with Quaker abolitionists and planted the moral fiber for a more compassionate union; where a vital Underground Railroad of whites and blacks shuttled more African Americans to and fro than SEPTA.

Yet, for some, the subject is inexplicably taboo. Verboten. Don't ask, don't tell.

Get over it, they say. It's in the past. Talking about it won't move us forward. Plus,


had nothing to do with it.

Ignore it or not,


all are affected by its cloudy residue.

But the good news is that with race in the open and conversations not just one-sided, more whites are choosing not to turn away and are honestly sharing their own history.

Last summer's excavation of the slave quarters at the President's House on Independence Mall and the ongoing slave reenactments at local churches are drawing white tourists and locals in droves.

Looking inward

Many, like Philadelphia first-time filmmaker Katrina Browne, 40, are doing some hard self-examination of their own family complicity in the business of chattel slavery.

In an effort to explore and reconcile her own ancestors' involvement in the slave trade, Browne made the illuminating documentary

Traces of the Trade: A Story From the Deep North

, which airs tonight at 10 on PBS.

To say Browne's family was "involved" in the slave trade is like saying Hitler was "involved" in the Holocaust. The DeWolf family - Browne's maternal descendants - was the largest slave-trading family in U.S. history.

The discovery left Browne mortified. For a while, she couldn't talk about it, even though in the back of her mind, she knew.

Browne, a graduate of Princeton and Pacific Lutheran Theological Seminary in Berkeley, Calif., had heard family stories of seafaring pirates and rapscallions. But it wasn't until she read the chilling account of the family's history written by her grandmother that her worst fears were confirmed: "The first DeWolfs that came to Bristol [Rhode Island] were slave traders," it read. "I haven't the stomach to describe the ensuing slave trade."

Worst of the worst

"In my mind, it was the worst thing you could do," Browne says. "Being a slave owner was horrible, but being a slave trader meant you were going to Africa and putting people in chains. . . . It ranked right up there with concentration camps."

A dubious legacy from which she reaps benefits, even today. And not just because Browne - the daughter of lawyer Stanhope Browne and civic historian Libby Browne - was raised privileged in a restored rowhouse in Society Hill.

"People are further along now as white Americans in ways that [they] take for granted," Browne says. "The government handouts that built up the white middle class - the GI bill, the redlining by banks that helped whites gain home ownership and denied blacks over and over again. . . . I hope this film helps people talk about this stuff."

Nine years in the making,

Traces of the Trade

chronicles Browne and eight relatives as they retrace the Triangle Trade, from the DeWolfs' hometown in Rhode Island to the slave forts in Ghana and sugar plantations in Cuba.

Every step of the way affirmed the vast extent of the family business.

"The biggest surprise was the degree to which the town was involved," she says. "Like people buying shares in the slave ships like they were buying shares in the stock market. It was horrifying to think of my ancestors talking themselves into this kind of inhumanity, but to see this interconnected web of complicity, the kind of mundane complicity that we do today . . ."

In this year, the bicentennial of the federal abolishment of the slave trade, all Browne is asking is for people to think, talk and, perhaps, even acknowledge.

And then, once its people acknowledge their history, maybe the government will have the will to extend the long-elusive apology - as England already has done.

"White Americans see apologizing for slavery as something they didn't do," Browne says. "You don't have to say you're personally responsible. But you can acknowledge and show some human compassion."