The Failure of Naval Action

Interestingly, none of these measures, except in part the assault in Brazil in 1850, was successful despite the fact that, by the mid-1840s, 10 percent of the British navy was deployed against the slave trade. Naval action, like slave revolts, raised the cost of doing business and therefore the prices of slaves in the Americas. Given a downward-sloping demand curve for enslaved labor, it thus reduced the number of Africans purchased and carried across the Atlantic.

Of course, because naval action increased risk for the slave traders, it also increased their profit rates. But naval action could not in itself halt the slave trade. Blockades have rarely been effective in history, and patrolling the sea off well-known ports of embarkation in Africa and disembarkation in the Americas did not spawn an exception to this tendency. So unsuccessful was the navy that, in Britain, a parliamentary campaign to withdraw the cruisers from anti-slave-trade duties came very close to success in the late 1840s.

The failure underscored a broader dilemma. Successful enforcement of human rights at the point of a gun is much rarer than many campaigners against abuses around the world are prepared to concede. In the past, slavery was destroyed by the application of force, but the attitudes that sustained slavery, as demonstrated by the case of the American South in the aftermath of the Civil War, are decidedly less susceptible to military action.

For the nineteenth-century slave trade, these general considerations imply that suppression could come about only when the regions that either dispatched captives across the Atlantic—phase one of the transatlantic movement of captives from Africa to the Americas—or the regions that received those captives—phase three—decided to take action.