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During the early 1980s historian Peter Linebaugh and I decided to write a book about transatlantic currents of radicalism in the seventeenth and eighteenth centuries. It was a project that eventually became The Many-Headed Hydra: Sailors, Slaves, Commoners, and the Hidden History of the Revolutionary Atlantic (Beacon Press and Verso Books, 2000). But as I conducted research in southern colonial newspapers, poring over accounts of conspiracies, mutinies, and revolts by workers of all kinds, I noticed something else. It was a kind of communication that appeared repeatedly in every paper published in or near a port city: advertisements written by enslavers about fugitives who had escaped bondage by sea.

I found one curious sentence in the ads that was repeated over and over: “Masters of vessels are warned not to employ or harbor said runaways nor to take them away, or they will face the full penalties of the law.” Runaways were not specifically part of our project, but I was intrigued and began to gather material about them. I placed photocopies of the ads in a file labeled “Things I found while looking for something else.”

The file grew fatter over time. One fascinating case after another hinted at what I began to call a “maritime underground railroad.” One of my favorite figures was a man named Caesar, who ran away in 1759. He had worked on the waterfront. His enslaver believed he would try to escape as “the Cook of a Vessel, as he has been much used on board of ships.”

Caesar was apparently recaptured, for he ran away again ten years later – two escapes despite his “having no legs.” He had no easy walk to freedom, but Caesar and his fellow fugitives had captured my imagination. I began to create new files under the rubric “maritime runaways.” My chance discovery grew into something bigger. In 1990, I pulled together this expanding body of material for a plenary lecture I had been invited to give at the annual meeting of the American Society of Eighteenth Century Studies in Minneapolis.

My subject? “The Maritime Frontier of Freedom.”

But that book had to wait. Conceptualizing, linking, and analyzing the acts and traditions of resistance in Europe, Africa, the Caribbean, and North America in The Many-Headed Hydra proved to be a challenge, and a lot of the research we did for the project did not make it into the final manuscript. Maritime runaways were one group of rebels among many who were not included.

But the paths of scholarship are slow and crooked, or so they have always been in my experience. I forgot about neither the people nor the topic in those bulging files, and three decades later I circled back around to take a fresh look. In 2020, my collection of documents about Caesar and his fellow rebels became the foundation of a new book tentatively entitled “Freedom Ship: Escaping Slavery by Sea in Atlantic Antebellum America.”

How does a writer travel the distance between an accidental discovery and a book project?

There probably exists no general rule about how such a thing happens, but here was my experience.

I started with what drew me to these documents in the first place. What fascinated me about the warning to ship masters was the social world that lay behind it. The phrase—“Masters of vessels are warned not to employ or harbor said runaways nor to take them away, or they will face the full penalties of the law”—revealed an important fact: running away by sea was a process through which fugitives cooperated with other waterfront workers, Black and white dockworkers and sailors in particular, in order to free themselves. The runaway sought the anonymity of a port city; the seamen sailed the vessels into and out of port; stevedores loaded and unloaded the vessels; cartmen and porters moved commodities from the waterfront into landed circuits of exchange.

It slowly dawned on me that the prospect of freedom for a would-be runaway depended on a complex world of work and negotiation. Instrumental to emancipation was a hitherto unexplored labor history, or so I imagined.

Perhaps I overestimate the coherence of what I understood when I first read those runaway advertisements. After all, the path from discovery to new book ultimately ran through six other books – about Atlantic sailors, rebels, maroons, outlaws, abolitionists, and revolutionaries, all about labor and resistance in various maritime contexts. They represented more than thirty years of research and writing. But as my knowledge advanced, so did my understanding of the original find. What I learned about the social world of the ship and the waterfront made me want to explore the meaning of that phrase “Masters of ships are warned ….”

Meanwhile, I had intellectual puzzles to solve. Many hundreds if not thousands of enslaved people emancipated themselves by escaping slavery by sea and many dozens of first-rate scholars had read those same runaway ads that I had read. Why did other historians never write at any length about escape by sea?  Why were these dramatic tales of whispered conspiracies, hiding away below deck, billowing sails, and ultimately liberation so rarely told? 

Part of the answer lay in American popular culture. The dominant image of the runaway is a woodcut that appeared in many nineteenth-century newspaper advertisements: a man or woman, simply dressed and usually barefoot, walking on land, carrying a bindle or a sack over his or her shoulder.

This representation implies that absconding was an individual act and indeed, this has become the prevailing scholarly judgment: running away was an individualistic response to enslavement, often contrasted with the much less common collective resistance of insurrection. Over time I came to see that both the implication and interpretation of these images are wrong. Not only was running away commonly undertaken as a collective act, the process of escape, as the warning to ship masters suggested, was fundamentally social, requiring collaboration and alliance even for someone who tried to go it “alone.”  Lateral social cooperation and connections, especially along the docks, were critical to a successful passage to freedom.

Another reason for historians’ blindness to mass escape by sea, I came to understand, is that the guiding metaphor “underground railroad” had long pointed in the wrong direction. The concept limited the vast majority of historical investigations to the land routes by which runaways traveled northward, even though the way to freedom included not only an underground railway, but another we might call an “over-sea freeway.” I have now learned that a majority of runaways arrived in places like Philadelphia, New York, and Boston by sea, even though the huge literatures on slave resistance and abolitionism say little or nothing about this central fact.

This scholarly blinkering also had a deeper cause, something I struggled for years to understand.  It is a curiosity in the sociology of knowledge. Why do most people, including most scholars, think of the oceans and seas of the world as ahistorical voids, as blank spaces between the “real” places of the earth that are both landed and national?

A few years after writing The Many-Headed Hydra I invented a concept to describe this deep, largely uninspected bias in our thought, the unconscious tendency to think that history happens only on land. In one of my books, I named this bias “terracentrism.”  It blinds us to the way in which specific historical events, such as the struggle against slavery, and larger historical processes such as class and race formation, happened at sea.  Seafaring people have usually been marginal to nationalist historical narratives, but they are increasingly visible in oceanic, transnational, and global histories. The labor of sailors connected the nations and the continents. Seafarers built the global economy.

By the time I came back to the subject of escaping slavery by sea in 2020, important work had been done on the subject, especially by David S. Cecelski on North Carolina (2001) and Cassandra L. Newby-Alexander on Virginia (2017). Timothy D. Walker has recently edited and published an important collection of essays, entitled Sailing to Freedom: Maritime Dimensions of the Underground Railroad (Amherst: University of Massachusetts Press, 2021).  Even so, the maritime history of the struggle against slavery, by self-emancipating people in the south and abolitionists in the north, remains severely understudied.

I returned to the file marked “Things I found while looking for something else” more than once. I wrote another book, The Fearless Benjamin Lay: The Quaker Dwarf who became the First Revolutionary Abolitionist (Beacon Press, 2017), which also emerged from research on The Many-Headed Hydra. But most of the items I placed in that file did not result in books, articles, or writing of any kind. 

Why did the maritime runaways draw me back? In retrospect, the hook had two shanks, two bends, and two barbs: the story was largely unknown and it was dramatic. I saw that this would be a riveting tale to tell, full of courageous people and daring action. And there was something going on in 2020 that made the discovery of the late 1980s all the more alluring: I came to see that escape by sea, and the emergence of abolitionist groups such as the Vigilance Committees to assist the runaways, was an early example of a migrant solidarity movement, the likes of which activists have now built around the world to assist dispossessed people in search of freedom. 

In that phrase, “Masters of vessels are warned …” lay a telling clue about how to study self-emancipation from below.  The stone the builder refused became the cornerstone of a new edifice.

Marcus Rediker is Distinguished Professor of Atlantic History at the University of Pittsburgh.  His “histories from below” have won numerous awards, including the George Washington Book Prize, and have been translated into seventeen languages worldwide.  He has also produced a film, Ghosts of Amistad, with director Tony Buba, and written a play, “The Return of Benjamin Lay,” with playwright Naomi Wallace.