In 1788, John Marshall made a prediction that was more prescient than he realized: The federal courts the new Constitution called for would be “the means of preventing disputes with foreign nations.” Marshall could not have known it, but for the next several decades international disputes over persons, ships, and goods caught up in maritime war would wash onto American shores, and into federal courtrooms. The courts’ decisions were essential to the United States’ emergence as a sovereign and independent nation. But preoccupation with Marshall’s famous constitutional rulings has obscured this story of judicial nation-building at sea. And while we have grown accustomed to the idea that “foreign affairs” are the domain of the legislative and executive branches, the political leaders who first tried to solve the puzzle of constitutional governance did not hew to such rigid notions of institutional responsibility. If Marshall’s legacy is the establishment of both judicial and national authority, this book shows that he and his contemporaries did so, first and foremost, at sea.

Americans understood the importance of establishing judicial authority over maritime war from the moment they began resisting British hegemony in the 1770s. The states’ unwillingness to prevent American seafarers from violating the rights of foreigners during the American Revolution provoked diplomatic controversies that undermined the drive for independence. After the war, supporters and skeptics of the new Constitution fiercely debated its creation of a federal judiciary. Anti-Federalist critics feared the centralizing and despotic tendencies of life-tenured judges who would be “subject to no control.” But even the “most bigotted idolizers of state authority,” Alexander Hamilton famously wrote in The Federalist, agreed that the federal courts should have exclusive authority over maritime cases. If Americans truly wanted a government that could fulfill the nation’s international obligations and maintain harmony with other sovereigns, they needed a judiciary with the power to resolve disputes arising at sea.

This chapter surveys one of the most significant enterprises of the Committee of Instruments and Proposals, established by the Board of Longitude following the Longitude Act of 1818. This was the management of a new observatory proposed for the Cape of Good Hope. Several Commissioners of Longitude had direct interests: John Barrow had been administrator and surveyor at the Cape; Joseph Banks advised on maritime surveys there; Davies Gilbert lobbied actively for a southern equivalent of the Royal Observatory. Commissioners successfully negotiated the scheme with the Admiralty and the Colonial Office. Though funds were forthcoming from the Navy, long-distance management proved difficult. The resulting issues reached the Committee and the Board, as did increasing costs of equipment from London’s finest instrument makers. These challenges had not been resolved at the Board’s dissolution in 1828; indeed, that moment coincided with discussions as to the possibility of closing the observatory. The affairs of the Cape Observatory thus reveal both opportunities and challenges in issues of scientific and geographical management in the epoch of empire and reform.

This chapter reinterprets the demise of the Board of Longitude in 1828, which has been seen as resulting from reformist pressure or financial retrenchment. Such accounts underestimate continuation of the Board’s activities, notably managing chronometers, producing the Nautical Almanac and providing scientific advice. Changes were initially driven by Joseph Banks’s interests, notably the appointment of Royal Society fellows and Resident Commissioners including Thomas Young, who became secretary and a key organiser after Banks’s death. Schemes such as rewards for finding the Northwest Passage, improvement of optical glass, determining the figure of the Earth and the foundation of the Cape Observatory, were managed under Young’s aegis. The role of the Admiralty and its Secretaries John Wilson Croker and John Barrow were decisive. The Longitude Act of 1818 brought the Board under Admiralty control, and that of 1828 moved its work into the Admiralty. An Admiralty committee comprising Young and natural philosophers Michael Faraday and Edward Sabine was formed; the Nautical Almanac and chronometer testing remained within the Admiralty’s financial remit.

The chapter charts the cultural and literary responses to the British Admiralty’s decision to explore the Arctic after the conclusion of the Napoleonic Wars. The main impetus for launching these explorations was reports of vanishing sea ice. Because it was erroneously thought that ice had hemmed in the Eastern Settlement on Greenland’s east coast, hopes were raised that the Admiralty’s Arctic programme would lead to a recovery of the ‘lost colony’. Several studies have dealt with Britain’s early nineteenth-century ambitions in the Arctic, but the role Greenland played in these considerations has not received the attention it warrants. By collecting and juxtaposing diverse sources, the chapter produces a new perspective on British imperial thinking. Focus is on how the hope of discovering the lost European settlers of Greenland was expressed in several nationalist poems published around 1818. Among the poets examined in the chapter are Anna Jane Vardill and Eleanor Anne Porden, whose verses about British interest in Greenland are analysed.

In Chapter Three, I move beyond plantation America’s shores to trace how the legal logic of chattel slavery projected out into the Atlantic Ocean. The idea that human beings could be treated as things at law was not landlocked. Rather, it was a legal concept that also infused the worldview of those who labored at sea. This becomes clear when we sift through the claims of the countless sailors, captains, and merchants who brought their disputes to colonial Vice Admiralty Courts, which governed life on British naval and merchant vessels. Litigants quibbled over many things in colonial Vice Admiralty Courts, but what united their disparate claims was an overarching assumption that people of African descent were valuable commodities. Vice Admiralty procedure helped to make this possible. Although English admiralty law had developed over centuries to allow European sailors and merchants to seize cargo and ships, Vice Admiralty litigants and judges extended the Courts’ in rem jurisdiction to include slaves found on captured vessels. This process of adaptation was silent and uncontested. Litigants, lawyers, and judges assumed arguendo that Vice Admiralty Courts could treat slaves as they would any other type of marine property. Without comment, they slotted enslaved people into ready-made forms and procedures, and brought black bodies before the Courts as objects that could be condemned, appraised, and sold.