About

Gregory O'Malley is a historian specializing in slavery, the slave trade, and early America. He is a professor and the chair of the History Department at the University of California, Santa Cruz. His research focuses on the Atlantic world, African diaspora, and colonial British America, with particular attention to the networks and movements of enslaved Africans across the Americas. His first book, Final Passages: The Intercolonial Slave Trade of British America, 1619-1807, examines the brutal network responsible for distributing enslaved Africans throughout North America and the Caribbean after their survival of the Atlantic crossing. O'Malley is also the co-creator of the Intra-American Slave Trade Database, a free online research tool documenting over 35,000 human trafficking voyages within the Americas. His forthcoming second book, The Escapes of David George, explores the life of an enslaved man in colonial Virginia, highlighting resistance, escape, and the quest for emancipation during the American Revolution. O'Malley's work has been recognized with multiple awards, including the Forkosch Prize, Rawley Prize, Owsley Award, and Goveia Prize, reflecting his significant contributions to British, Atlantic, and Caribbean history.

Research topics

• Computer Science
• Chemistry
• Materials science
• Physics
• Archaeology
• Electronic engineering
• Optoelectronics
• Mechanical engineering
• Geography
• Electrical engineering
• Engineering

Selected publications

• Jane Webster. 2023. Materializing the Middle Passage: a historical archaeology of British slave shipping, 1680–1807. Oxford: Oxford University Press; 978-0-19-921459-4 £130.

  Antiquity · 2025-05-15

  articleOpen access1st authorCorresponding

  In the concluding chapter of Materializing the Middle Passage, Jane Webster asserts that "it is possible to materialize many aspects of the Middle Passage" that millions of African captives endured as one section of the trade route that took enslaved Africans to the Americas and West Indies; however, she then acknowledges that "in that endeavour, I have needed to draw primarily on the written testimonies of the sailors who crewed the ships" (p.439).The result of the tension captured in those sentences-between Webster's interest in material culture and her necessary reliance on textual sources-is a unique and fascinating book about the trafficking of enslaved Africans on British ships.Materializing the Middle Passage combines an archaeologist's focus on goods, crafts and built environments with (mostly) the textual sources of historians, although Webster makes great use of art and material artefacts wherever possible."There are other ways to excavate the slave ship," Webster insists, than relying on the discovery and exhumation of shipwrecks (p.2).Explicitly embracing historical archaeology, Materializing the Middle Passage seeks to "marry words and things" (p.5).Webster brings together the material and textual remains of the British Atlantic slave trade not only through inter-disciplinary methods but also relentless research.To uncover the shipboard environments and experiences of the Atlantic crossing, Webster investigates the excavation records of all known slave-ship wrecks, artworks by eyewitnesses depicting slave ships, testimonies from UK parliamentary investigations of the slave trade, and surviving journals and autobiographies from crew members and captives alike.Taking a capacious view of the Middle Passage, Webster also looks beyond the seaborne voyages of captives and sailors from Africa to the Americas to investigate the commodities that Europeans delivered to West African societies in exchange for captives, the changing African representations of Europeans and their ships in art and iconography, and memories of the ocean crossing in the communities that enslaved people created in the Americas.It is a staggering research effort, and I imagine readers from any discipline will be exposed to new material.As a historian of the slave trade, I found most of Webster's textual sources familiar, but I had encountered only a fraction of the art, shipwrecks and material remains upon which she draws.Even familiar sources were interpreted from a fresh and intriguing perspective.On the surface, Materializing the Middle Passage is about 'things' but the book is really about mindsets.Webster deploys the material record and textual evidence about the slave trade's environments and conditions to explore the worldviews of both the traders (European and African) and those people they traded.Through coats of arms and displays of

  PublisherOA PDFDOI

• High-Power Micro-Ring Modulator and Multi-Channel Coupled Ring Resonator for WDM Design on a 300-mm Monolithic Foundry Platform

  Optical Fiber Communication Conference (OFC) 2022 · 2024 · 2 citations

  • Materials science
  • Optoelectronics
  • Electrical engineering

  We present scaled, bidirectional silicon photonic ring modulator and multi-channel coupled ring resonator models, offering advanced simulation capabilities for high-power and thermal time constant analysis, facilitating comprehensive on-chip EO system design with GlobalFoundries PDK.

  PublisherDOI

• : <i>Staging Holiness: The Case of Hospitaller Rhodes (ca. 1309–1522)</i>

  Renaissance Quarterly · 2024-03-01

  article1st authorCorresponding
  PublisherDOI

• A bioavailable strontium isoscape of Angola with implications for the archaeology of the transatlantic slave trade

  Journal of Archaeological Science · 2023 · 18 citations

  • Archaeology
  • Geography

  The region of present-day Angola was one of the main areas from which millions of enslaved Africans were abducted and forced to migrate to the Americas during the transatlantic slave trade. Strontium isotope (87Sr/86Sr) analysis is a useful tool in reconstructing large-scale human movements across geologically distinct landscapes in archaeological and forensic contexts. However, the absence of environmental 87Sr/86Sr reference data from Angola hinders the use of 87Sr/86Sr analysis in provenance studies related to Angola, especially in identifying the geographic origin of enslaved people in the African Diaspora. Here, we measured 101 plant samples from most, yet not all, major geological units to draft the first bioavailable 87Sr/86Sr map (isoscape) for Angola using a machine learning framework. Our results suggest that the 87Sr/86Sr ratios in Angola span a large range from 0.70679 to 0.76815 between the different geological units. Specifically, the high average 87Sr/86Sr ratios of 0.74097 (±0.00938, 1 SD) found in the Angola Block of central Angola, are distinctly more radiogenic than any previously published bioavailable 87Sr/86Sr ratios for western Central and West Africa. However, these match the 87Sr/86Sr ratios previously published for human enamel samples from four historic slavery contexts in the Americas. We demonstrate that our strontium isoscape of Angola greatly improves the ability to assess the possible origins of enslaved African individuals discovered outside of Africa and encourage the future use of emerging African isoscapes in the study of life histories within the slave trade.

  PublisherDOI

• The Last Slave Ships: New York and the End of the Middle Passage by John Harris (review)

  The Journal of Southern History · 2023-07-28

  article1st authorCorresponding

  Reviewed by: The Last Slave Ships: New York and the End of the Middle Passage by John Harris Gregory E. O'Malley The Last Slave Ships: New York and the End of the Middle Passage. By John Harris. ( New Haven and London: Yale University Press, 2020. Pp. xii, 300. Paper, $22.00, ISBN 978-0-300-26149-3.) In The Last Slave Ships: New York and the End of the Middle Passage, John Harris investigates the Atlantic slave trade's last decade, offering a riveting and deeply researched account of international trading networks that formed to defy growing barriers against human trafficking. By 1852, Cuba stood virtually alone as the Atlantic slave trade's final destination, but Harris shows that more than 200,000 people endured the Middle Passage in the 1850s and 1860s, with traders based in the United States playing a pivotal role. Despite American laws prohibiting deliveries of Africans to the United States and barring American merchants from trafficking to other countries, Harris exposes how U.S. ships, ports, traders, and policies sustained the Atlantic slave trade to Cuba into the 1860s. He also reveals persistent efforts by abolitionists to close the loopholes that these "last slave ships" exploited. Harris's work enhances our understanding of the late years of the slave trade, the role of slavery in American politics and diplomacy, and the connections between slavery and the globalization of finance and capitalism. Chapter 1 offers background on the slave trade up to 1850, describing how international suppression efforts spearheaded by Great Britain closed most of the trade's transatlantic routes. This international diplomatic campaign culminated in an 1840s crackdown that closed Brazil—the largest remaining market in the Americas for enslaved Africans—prompting Portuguese and Brazilian traffickers to seek new bases. Chapter 2 focuses on what Harris calls the "final triangle," an emergent international coalition in the 1850s to perpetuate the Atlantic slave trade (p. 3). Displaced Portuguese and Brazilian traders, longtime suppliers in Angola who struggled to sell people as the trade contracted, and merchants and landowners in Cuba eager to find laborers cooperated to profit from Cuba's late-blooming plantation economy. The traffickers based themselves in New York for several reasons: the United States built the era's fastest ships; New York had long-standing ties to Cuba as a market for flour; and Britain's antislavery naval patrols could not board vessels flying the U.S. flag. Chapter 3 traces a full voyage of the ship Julia Moulton, examining life aboard such clandestine slaving vessels. Hiring aboard a slaver promised crewmembers high wages due to the legal risk. But Harris argues that some employers hid their intention to traffic people when hiring sailors. For captives, it was an especially dangerous era of the Middle Passage because traders carried shelf-stable provisions from the Americas rather than buying fresh provisions in Africa as a way to avoid coastal patrols. Likewise, African suppliers held captives in unhealthy coastal barracoons for long stints so they could be ready to load arriving ships at a moment's notice. Chapter 4 describes how governments opposing the slave trade deployed spies and informants to collect information on slaving voyages. Most notably, British consuls employed former trafficker Emilio Sanchez to inform on planned ventures in New York, because British officials feared that lax American enforcement of anti–slave trade laws undermined British suppression efforts. [End Page 565] Underscoring this argument about how U.S. laxity enabled the slave trade, chapter 5 shows how the rise of the Republican Party turned the tide. By enhancing enforcement of existing laws, passing new statutes to close loopholes, and increasing cooperation with Britain, newly elected Republicans quickly disrupted the "final triangle." Thus, Harris argues persuasively that the "United States proved to be critical to both the slave trade and its eventual suppression" (p. 243). Overall, The Last Slave Ships offers a compelling narrative and persuasive arguments, especially regarding the machinations of traders and the mixed records of governments that sometimes allowed the trade and sometimes acted against it. Harris also vividly describes the routes enslaved people traveled, their shipboard conditions, and the interplay of violence and resistance that shaped their interactions with...

  PublisherDOI

• Five Hundred African Voices: A Catalog of Published Accounts by Africans Enslaved in the Transatlantic Slave Trade, 1586–1936.<i>Edited by Aaron Spencer Fogleman and Robert Hanserd. Philadelphia, PA: American Philosophical Society, 2022. xliv + 513 pages + 17 maps + 1 photographic essay. $45.00 paperback.</i>

  Monatshefte · 2023-01-01

  article1st authorCorresponding

  Five Hundred African Voices: A Catalog of Published Accounts by Africans Enslaved in the Transatlantic Slave Trade, 1586–1936 . Edited by Aaron Spencer Fogleman and Robert Hanserd. Philadelphia, PA: American Philosophical Society, 2022. xliv + 513 pages + 17 maps + 1 photographic essay. $45.00

  PublisherDOI

• ‘In Tot Acerrimis Conflictibus’

  Routledge eBooks · 2022

  1st authorCorresponding
  • Computer Science
  • Computer Science

  This chapter will examine references made to the 1522 siege of Rhodes in grants made to both Hospitallers and non-Hospitallers in the months and years following it. Many appointments to commanderies referred favourably to appointees’ participation in the fighting, if in formulaic terms, while those who gave assistance to the Hospital during the struggle might be commended and rewarded in other ways. The language and substance of these documents will be analysed, and they will be compared with that issued after the siege of 1480 and with the language used to describe participants in the siege of 1522 in other sources produced by the order or influenced by its productions. The citations’ value as a source for verifying and adding to the lists of Hospitaller brethren who took part in the siege provided by Giacomo Bosio and what they tell us about experiences of the siege will also be examined.

  PublisherDOI

• Slavery, Captivity, and the Slave Trade in Colonial North America’s Global Connections

  Cambridge University Press eBooks · 2021-11-12

  book-chapter1st authorCorresponding

  Slavery connected North American colonies to a wider world in ways both obvious and subtle. Most obviously, forcing African people to toil in the New World introduced African knowledge, cultures, and languages into American societies, enriching not only slaveholders, but also American culture. African labor, skills, and traditions built American economies, shaped systems of production, and transformed American cuisine, music, and speech. Meanwhile, North American colonists adapted slavery’s caste system from precedents set elsewhere around the Atlantic. Slaveholding North American societies codified and elaborated systems to control the enslaved to suit their own ends and circumstances, articulating a racial division of rights and labor that uniquely constrained African American lives and subjected enslaved people to myriad abuses, but the basics of property in persons and hereditary servile status were imported.

  PublisherDOI

• Introduction 1

  2019-01-15

  book-chapterSenior author
  PublisherDOI

• The Countryside Of Hospitaller Rhodes 1306-1423: Original Texts And English Summaries

  2019-01-14 · 1 citations

  bookSenior author

  The Countryside of Hospitaller Rhodes 1306-1423 explores the main themes of settlement, population and defence of the countryside of Rhodes from 1306 to 1423, approximately halfway through the period of Hospitaller rule. Based largely on the Hospital's Rhodian archive, this book is the scientific presentation of 208 documents brought together with detailed English summaries to help readers understand the documents and their technical features. While the majority of research into this subject has previously been focused on the town of Rhodes, this book concentrates instead on the late-medieval countryside, providing a new angle from which to view this complex period. Through a corpus of Hospitaller texts, it presents many aspects of the Hospitaller Order's history as well as exploring other crucial developments in the period, including both a discussion of Cristoforo Buondelmonti's description of Rhodes, and a section dedicated to the sources used within this work. The Countryside of Hospitaller Rhodes provides an ideal for academics and postgraduates of the crusades

  PublisherDOI

Frequent coauthors

• Anthony Luttrell

  8 shared

• Alex Borucki

  University of California, Irvine

  4 shared

• Frank Pavlik

  GlobalFoundries (United States)

  1 shared

• Crystal Hedges

  GlobalFoundries (United States)

  1 shared

• Frederick G Anderson

  1 shared

• Qidi Liu

  GlobalFoundries (United States)

  1 shared

• Petar Todorov

  Bulgarian Academy of Sciences

  1 shared

• Colleen Wemple

  GlobalFoundries (United States)

  1 shared

Awards & honors

• Public Scholar Fellowship, 2021, National Endowment for the…
• Digital Extension Grant, 2020, American Council of Learned S…
• Barbara S. Mosbacher Short-Term Research Fellowship, 2019, J…
• Edna and Norman Freehling Fellowship, 2016, Virginia Foundat…
• Humanities Collections and Reference Resources Grant, 2016,…