Over a century and a half after President Abraham Lincoln issued the Emancipation Proclamation, millions remain in bondage—children forced to take part in armed conflict or sold to brothels by their destitute families, men and women who toil for little or no pay, who are threatened and beaten if they try to escape.

Thus begins Barack Obama’s presidential proclamation inaugurating the 2014 National Slavery and Human Trafficking Prevention Month. It couches a humanitarian anti-trafficking appeal in the familiar terms of an anti-slavery struggle that—it is often said—continues to be waged. We see this suggestion in many contemporary campaigns to end human trafficking. Organisations such as New York’s New Abolitionists, Free the Slaves, and Anti-Slavery International portray themselves as carrying forward the crusade begun by the abolitionists who spoke out against the transatlantic slave trade. However, their educational campaigns often take up the mantle of ‘new abolitionism’ without addressing the mixed legacies of the abolitionism that they invoke. Furthermore, their efforts to raise public awareness often focus on the journey into trafficking and slavery, yet overlook the weight of the legal and social edifices built by modern states to curtail and prevent escape.

Mobility was central to political struggles against African chattel slavery and the indentured or bonded Asian ‘coolie’ labour used to supplement and replace it in the Atlantic economy. Slavery demanded the regulation of movement. Disciplinary control over black bodies in space was essential to the theory of mastery. “At the heart of the process of enslavement was a spatial impulse: to locate bondpeople in plantation space and to control, indeed to determine, their movements and activities,” writes the historian Stephanie Camp. Slave states restricted mobility in part through the use of passes and residency licenses that declared the bearer either property of someone else or freed (manumitted) resident of the state. Coastal slave states went even further by enacting Negro Seamen Acts. These prohibited the entry of free black sailors and quarantined them in local prisons for as long as their vessels remained in port (and under threat of enslavement if prison fees went unpaid).

Black spatial captivity was not limited to slave jurisdictions. Sojourner laws in northern states allowed slaveholders to travel through or remain on free soil for periods of time without forfeiting their human property. They worked in concert with the 1850 Fugitive Slave Law, which compelled northern citizens and agencies to aid in the recapture of runaway slaves. Moreover, transatlantic anti-slavery activists such as Frederick Douglass and William Wells Brown discovered that manumission or legal freedom did not confer federal recognition when the State Department denied their passport requests on the basis of race. State and federal governments acted on their powers to determine who circulated within and crossed their borders; they systematically restricted black mobility.

Historical abolitionists began explicitly identifying personal liberty with the freedom of movement in their print and legal campaigns. They traced this concept back to William Blackstone’s Commentaries on English Law: “personal liberty consists in the power of locomotion, of changing situation, or removing one’s person to whatsoever places one’s own inclination may direct, without imprisonment or restraint.” This right of locomotion was essential to freedom, just as its denial was essential to enslavement. It constituted a theft of birthright that was synonymous with the theft of person in slavery.

The end of legal slavery held out the promise of a world in which mobility was no longer restricted, policed, and criminalised. For the newly liberated, wrote the scholar Saidiya Hartman, “the sheer capacity to move…provided the only palpable evidence of freedom.” Abolition, however, did not ease the destructive impact of white racism or protect the liberated from new forms of captivity, from forced labour contracting, debt peonage, and sharecropping to convict leasing programmes. At the dawn of the twentieth century, the emerging legal architecture of Jim Crow curtailed the freedom of movement in ways tragically continuous with the past era of slavery.

The types of exploitation often referred to as ‘modern slavery’ are exacerbated by immigration controls and the forms of spatial captivity they entail. Trafficking today remains largely understood in terms of involuntary transit or transfer, even though overt coercion may not have influenced departure, and the migration itself may have involved different degrees of legality. The earliest efforts to parse these differences took place in the context of historical abolitionism.

Just months before the Emancipation Proclamation, Lincoln signed the “Act to prohibit the ‘Coolie Trade’ by American citizens in American Vessels,” in response to public outcries against American participation in what was called ‘the yellow trade.’ The formal end of the transatlantic slave trade and domestic slavery precipitated wide-scale labour crises across the western hemisphere. The plantation economies of the US South and the British and Spanish Caribbean drove demand for disposable, cheap replacements from colonial India and China. The Coolie Trade Prohibition Act was America’s last slave-trade regulation and its first federal immigration restriction. It explicitly differentiated illegal human importation from immigration, and established certification of voluntary emigration as the condition of lawful entry into the US. This fundamental distinction between voluntary and involuntary migration has also structured more recent trafficking protocols, including the United Nations Protocol to Prevent, Suppress and Punish Trafficking in Persons Especially Women and Children.

Efforts to combat trafficking have “consistently translated into efforts to restrict movement.” As a consequence, trafficking prevention often encourages anti-immigrant policies that fortify national borders and further restrict legitimate movement in ways that are detrimental to migrants. The confiscation of passports and other documents make it difficult for trafficked persons to establish their legal identity or circumvent immigration controls. Even documented migrants caught up in the global networks of exploitative labour relations often find themselves ineligible for various forms of institutional relief. Relating the broader history of abolitionism to contemporary struggles against modern slavery helps us better recognise how transatlantic slavery and its prevention were both predicated upon a vast legal architecture of policing movement that bound the formerly enslaved to new forms of servitude after emancipation. To address contemporary forms of trafficking or ‘modern slavery’ without acknowledging the freedom of movement as a fundamental human right (one recognised by the Universal Declaration of Human Rights) inadvertently contributes to the problem and neglects the complex history of struggle to which ‘new abolitionist’ organisations lay claim.