Levi Coffin recounted life in the Underground Railroad in his memoir, writing ‘We knew not what night or what hour of the night we would be roused from slumber by a gentle rap at the door. That was the signal announcing the arrival of a train’.1 Coffin was a wealthy businessman driven by his Quaker beliefs who became involved with the Underground Railroad (UGRR) after moving to Newport, Indiana in the United States. The UGRR was a clandestine grassroots political movement made up of a network of volunteers that helped slaves in the southern states to escape and reach freedom in the northern free states or in Canada.In the 1800s slave labour drove much of the booming cotton industry in the southern states. When it became illegal to import slaves into the United States in 1808, those slaves currently in active service became ever more valuable to plantation owners, who lobbied for greater legal powers to prevent their escape. In 1850 the second Fugitive Slave Act was passed, which further tightened the legal requirement for escapees to be returned — even when captured in the northern free states where slavery was all but abolished.The UGRR came into being against this backdrop, partly in response to the tightening legislation. The people operating the UGRR used jargon relating to the railway, a prominent means of long-distance travel in the early 19th century. The train, figuratively speaking, referred to the network of escaping slaves, with each slave being a ‘passenger’. Safe-houses like Coffin’s own home, which provided refuge for the runaways, were known as stations; the hosts as stationmasters, and those who guided passengers between stations, the conductors. As Coffin recounted, ‘The connections were good, the conductors active and zealous and there was no lack of passengers’.2To reach the safety of the UGRR from the cotton fields, the escapees had to first elude their immediate pursuers, but even when navigating the long route north via the UGRR, they were in danger of being recaptured by independent bounty hunters. The conductors played a critical role here; Harriet Tubman was one of them.Tubman was born into slavery in the 1820s in the southern state of Maryland, and escaped in her twenties. A fervent Christian who drew courage from what she thought to be visions from God, Tubman is believed to have made at least a dozen journeys, guiding hundreds of escapees to safety. According to her contemporary biographer, she would arrange to appear on a plantation in the dead of night, where ‘a trembling band of fugitives’ was ‘anxiously awaiting their deliverer.’3 Tubman would then guide them north largely on foot, ‘scaling the mountains, fording the rivers, threading the forests’.4 Her activism earned her the title ‘the Moses of her people’, likening Tubman to the biblical Moses who led the Israelites from bondage in Egypt to freedom in the Promised Land — here Canada.The idea of Tubman as Moses appears to have been well-understood in the UGRR. On one occasion, according to her biographer, Tubman had left a party of escapees hidden in the woods whilst she sought sustenance from a UGRR station. The woods had been ‘scoured in all directions’ in an effort to find the fugitives, who were as a result terrified. Later while returning, Tubman is said to have sung the African-American spiritual ‘Go down, Moses’ (which includes the call to freedom ‘Tell old Pharaoh, Let my people go’) to signal her presence on her approach to camp.5Likening slavery in the United States to the plight of the Israelites of the Old Testament and Tubman as the Moses who leads them to freedom is an example of a Conceptual Metaphor,6 a term arising from cognitive linguistics. A conceptual metaphor is where an idea in a target domain is too abstract or complex to comprehend in its entirety, hence it is defined using commonly understood terms in the source domain. Here the target domain is slavery in the United States, an enormously complicated socio-political phenomenon. However, the people of the UGRR were able to create a meaningful discourse around this by using a well-understood biblical story as the source domain. The UGRR itself is a conceptual metaphor; the abstract idea of freedom (the target domain) was understood in terms of a concrete train journey (the source domain).Conceptual metaphors help us to deal with complex phenomena by relating them to things we understand. As such their use is ubiquitous. For example, we talk about fighting, bleeding, and dying for love. Here the target domain is love, which we attempt to comprehend through the easily grasped idea of war. The railway metaphor as embodied in the UGRR, however, is what is known as a culturally unique conceptual metaphor, because the escape north via the ‘railroad’ was unique to the context of slavery in the United States. This kind of metaphor is fairly unusual, and this creative way of thinking about escape possibly contributed to the establishment of a very effective network.7The UGRR eventually became obsolete when in 1865 the 13th amendment to the American constitution declared slavery and ‘involuntary servitude’ to be illegal in every state. When the 15th amendment of 1870 subsequently gave men of every race the right to vote, Coffin wrote ‘our underground work was done [...] I would suggest that the rails be taken up and disposed of, and the proceeds appropriated for the education of the freed slaves’.8