At the bottom of the ladder of wealth and prestige, slavery continues to resist pat categorization.

This year being the 200th anniversary of the abolition of the British slave trade, there has been a fair amount of sober reflection on the iniquity of that institution. There's been a fine movie, Amazing Grace, and some useful contemplation upon the "original sin" of the American republic. But there's also been a wholly insufficient amount of attention paid to the persistence of slavery in the world.

Anniversary commemorations tend to give the impression that single events neatly divide history into chapters, but history rarely works that way. It's also rarely so straightforward that the people and forces that shape history can be contained within convenient categories. The history of slavery, for instance, is routinely considered in the context of colonialism and racism, specifically the European enslavement of Africans. But this overlooks some fairly important exceptions and contradictions.

Last month, historian Afua Cooper, writing in the Toronto Star, made a convincing case that "Euro-dominated governments" such as Canada's have failed to adequately address their complicity in the African slave trade. But another historian, Robert Davis, has pointed out that North Africans captured at least a million Europeans and sold them into slavery between the 16th and 19th centuries. And what of the tens of thousands of Irish that 17th-century British slavers sold into slavery in the Caribbean?

Another contradiction is the case of British Columbia, where slavery was an institution that was central to the coast's highly sophisticated and class-stratified aboriginal societies. It was colonialism, mainly, that brought the institution to an end.

As anthropologist Leland Donald pointed out in his landmark 1997 work, Aboriginal Slavery on the Northwest Coast of North America, slaves played important roles as labourers, status symbols, and trade commodities throughout the Northwest Coast culture area. Slaves were sometimes captives taken in warfare and rendered into chattel, but many were also born into slavery. Chiefs were known to slaughter slaves in ritual displays of wealth, or in marking important community events, such as the raising of a heraldic pole.

James Douglas, the governor of the Colony of Vancouver Island, and later British Columbia's governor, was an ardent abolitionist who kept his officers under strict instructions to suppress aboriginal slavery. Alternatively described by his contemporaries as a mulatto, a creole, and an octoroon, Douglas could count African slaves in his own ancestry.

Long before the American Civil War resulted in the emancipation of the slaves in the United States, Douglas was leading annual celebrations of Emancipation Day in Victoria, commemorating the prohibition that finally freed all the slaves throughout the British Empire on August 1, 1834. In the late 1850s, American gold miners–many from American slave states–began pouring out of ships in Victoria harbour. For many of them, their first encounter with British authority was the sight of the all-black "African Rifles", a Victoria militia.

Canada is commonly described as having been at least a minor slave state that ended up a pioneer in slavery's abolition. In their respective statements marking the 1807–2007 bicentennial last month, both Stephen Harper's Conservative government and the opposition Liberal party cited a 1793 antislavery law that made Upper Canada the first British jurisdiction to move toward full abolition. A similar law followed in Lower Canada in 1803.

It's true that only about 5,000 people are believed to have been slaves in Canada throughout this country's history, while almost four million people were enslaved in the United States the year the Civil War broke out. But it would be wrong to conclude from this, or from the enduring stories of the "underground railroad" that brought escaped slaves from America to freedom in Canada, that we Canucks beat the Yanks in the race to the moral high ground on the matter of slavery.

The United States failed to fully abolish slavery until 1865, and it's also fair to argue that in the Deep South, at least, abolition was largely a paper exercise for many years after that. But Vermont abolished slavery outright in 1777, a full 16 years before Upper Canada's partial abolition. And Vermont was followed quickly by Pennsylvania, Massachusetts, and several other northern states, well ahead of Upper Canada's 1793 law. And in 1787, the United States Congress outlawed slavery in the territories that would become the Midwest states.

It just goes to show. History doesn't neatly stop and start in convenient chapters, and history doesn't always fit into convenient categories.

If you place an overemphasis on race and colonialism, you'll overlook the category of class, where slavery more fundamentally belongs, at the very bottom rung of a hierarchy of wealth and power. If you fail to notice that, you'll fail to pay sufficiently urgent attention to the present. You might completely overlook the fact that today, slavery is big business. It's bigger than it's ever been.

The contemporary global slave trade is worth roughly $32 billion. Today's slaves are routinely children. They are sex slaves in Southeast Asia, field labourers in India and Turkey, textile workers in Bangladesh, and house servants in Chad.

The United Nations estimates that around the world today, between 12 million and 27 million people are slaves.

The Chronicles blog can be found at www.transmontanus.blogspot.com