For years, here in New England, we’ve been able to feel a little smug with respect to the history of slavery: it was an issue that took place particularly in the old red states. We in Massachusetts, after all, pretty much got done with the peculiar institution by the time the Commonwealth became a State. And our economic system, we felt, didn’t really support slavery like the plantation system in the South did.

By and large, those few of us who read history knew, we’d been on the right side of the issue: Boston was a hotbed of radical abolitionism, and if the great Daniel Webster had been willing to sell our morals down the river along with escaped slaves in 1850 (supporting the Fugitive Slave Act), at least we immediately upon his demise elected the anti-slavery Charles Sumner , who was subsequently caned to within an inch of his life on the Senate floor.

Wrong. Or perhaps I should say, "wrong question." Legal emancipation (by 1800, the Massachusetts census showed 1400 or so enslaved souls) and the fact of a small farm and trade-based economy aren’t the only, best, or even good indicators of New England participation in the system of enslavement of millions of Africans.

As we have we started to see history on a more systemic scale than as the stage upon which great men act, the story of slavery in New England isn’t so much new as it is re-visited — the glance, refocused. One gets to feel a lot less smug that way.

As a historian, I knew that there’d been chattel slavery in New England, that much of the cotton fabric produced in our early industrialization went to the plantations; and that Rhode Island was a center for slave trading. But I did not quite put it all together: No New England participation , no plantation system. No New England slave trade — much less tsuris in the world today.

Well, I do get it now. To begin with, I saw Katrina Browne’s new documentary, Traces of the Trade. Descendants of the largest slave-trading empire New England ever saw, the deWolf brothers, figured out what their ancestors, known to them as "those pirates," had really been up to. The film follows the descendants on a journey of discovery from the Bristol, RI, Historical Society, to Ghana, to Cuba, and back to New England to change the world.

The film got me the moment these people opened a file cabinet with deWolf papers, found a gravestone marked with the name of one of their ancestors’ own slaves, and visited the deWolf warehouse at the Bristol harbor. These are the kinds of places I like to poke around in. Dusty files, overgrown graveyards, dilapidated buildings. Together, they tell a story of New England complicity: these traders didn’t hide what they were doing , it was common knowledge. It was normal at the same time that it was common knowledge that it was wrong.

Wrap your head around that, to use a phrase of Katrina Browne’s. Everyone in Bristol knew where deWolf money came from. Moreover, everyone and their mother in Bristol bought shares, Connecticut and Massachusetts farmers provisioned the ships, Massachusetts shipbuilders built the ships. Just to mention a few examples.

And how do I know it was common knowledge that it was wrong? Well, it was outlawed, as of 1790, for U.S. citizens to engage in the "slave trade to foreign ports." In 1794, it also became illegal to "manufacture, equip, or otherwise assist any vessels destined for the slave trade." And starting on January 1, 1808, the importation of slaves into the United States was outlawed. The deWolf Brothers plied their trade before, during, and after these laws, not really stopping until slave trading became defined as piracy, and piracy a capital crime. That was in 1820.

But by that time, New England was so deeply involved in supplying plantations with all sorts of goodies they needed, like whale oil, cotton, and food, that the relatively minor influence of getting new slaves from Africa became a drop in the economic bucket. If George deWolf’s 1825 bankruptcy sent Bristol’s economy reeling, it was as much because of investment in his Cuban plantations as in his ships.

Joanne Pope Melish, author of Disowning Slavery:gradual emancipation and "race" in New England, 1780-1860, argues that New England slavery became invisible because it didn’t look like factory-style plantation production. Instead, slaves in New England functioned economically like women , they did not necessarily do the same work, but like women they minded the farm, thus freeing up white men, one at a time, to do a lot of governing and economy-building. This made them literally invisible: economists do not count their work as part of production, and so they fall off the radar screen. I’d call that systematic erasure , worker exploitation for the long haul.

Nathan Nunn, a Harvard economist, has amassed figures to show that Africa’s current economic woes are directly related to the slave trade (Boston Globe, 4/20/2008). He correlates the places that suffered the most human pilferage to those that are now poorest, and to those where people are the least able to trust other people. Without entering into the question of whether Nunn’s figures are right or wrong, one might note this: whereas Nunn has a lot of information available about the transatlantic slave trade as plied by American traders, his bases for looking at the inland-to-coast trade are much sketchier the historic excavation simply hasn’t been done. Another instance where people haven’t been counted?

Traces of the Trade raises powerful questions for this public historian, not only about research, acknowledgement, reparation, and apology. But it also won’t leave me alone about my own participation in dubious trade and dubious historical practice , and my willingness to overlook it.

My shoes? Read worker exploitation. Lowell? Read ‘worker exploitation’ and ‘the economy of slavery.’ The China Trade of the nineteenth century? Read, Opium Trade. New England banks? Read: all of the above. New England museums and historical places: read ‘most of the above.’ But will people even show up if we, public historians, tell tales of nothing but moral turpitude instead of heroic invention and adventure?