Bayard had vested many of his hopes in the commission of the Jay Treaty's London commission. In Article VII, the Jay Treaty specified that five commissioners were to meet in London for eighteen months to discern and evaluate: “Complaints […] made by divers Merchants and others, Citizens of the United States, that during the course of the War in which His Majesty is now engaged they have sustained considerable losses and damage by reason of irregular or illegal Captures or Condemnations of their vessels.”

The aim of this commission was to agree on and pay out an “adequate Compensation” to such merchants, to be covered by the British (or American) government. This systematic and formalised arbitration was new, introducing what has been termed as “the modern era of arbitral or judicial settlement of international disputes”.

For the London commission, American commissioners Christopher Gore and William Pinckney were ‘mixed’ with British commissioners, Dr Nicholl (who later resigned to take on the position of King's Advocate and was replaced by Maurice Swabey) and John Anstey. Therefore, the commission “consisted chiefly of lawyers with a wide cultural background”. Gore had studied law under John Lowell, a judge on the US Court of Appeals in Cases of Capture – the first federal US court and incidentally a law court that dealt in prize.

The Jay Treaty was published by the US government and widely disseminated in the press. Known as one of the first outcries in American politics and infamous for the public reaction to it, its circulation can barely be underestimated. 1 But how did US merchants interact with the commission or with Bayard in his capacity for assistance in claims and appeals? What information did the US government provide to mercantile communities, in which manner did they themselves interfere with the court process, and how was such information circulated?

Merchants were already following regular updates on condemnations and captures, both in the vice-admiralty courts and in the High Court of Admiralty. Decrees and lines of argumentation in court were published in newspapers.2 John Proctor obtained knowledge “by a late Bermudian paper, that the Ship Hamilton, Capt. Farrett, was taken by the Thetis British Frigate, and carried into Bermudas”3 and thus took up correspondence with the US government. Some government instructions had been printed in American newspapers, even printed in their entirety, with specific references made to the importance of providing merchants with information.4 The merchant community also functioned as a communication network in itself, with two merchants corresponding in 1797, whether they should contact other persons who might be in a similar position concerning captured property and get them in touch with Samuel Bayard.5 Yet the knowledge of what exactly the Treaty meant for their private cases remained unclear to many. The main initial point of governmental contact for most queries was the Secretary of State, although individual members of the commission, and additional staff on both sides, such as Jacob Wagner, Chief Clerk at the State Department, or Samuel Bayard, all received letters. Occasionally, citizens were referred there by other government officials.

Many studies have been published on the development of maritime courts. Maritime courts (including admiralty jurisdiction) and their existence as part of an international network of common legal ground have been traced back in time through the ages. Some researchers trace this common European legal practice through the codifications of the Consulato de Mare, the Black Book of the Admiralty, Rhodian sea law, to the Tabular Amalphitana, the Rôles d’Oléron, Jerusalem or the Baltic and Hanseatic states. Other experts emphasise that merchant and consular courts had been prevalent previously. Merchant courts reflect how commercial communities found measures to ensure their interests in maritime trade. Such measures were gradually taken over by the state. Consular courts show a different approach to issues of the marine, not focusing on commercial business as a common denominator, but instead highlighting the international character of maritime trade interactions. Consular courts reduced the possibility of individuals later claiming to have been wronged as foreigners and gave leeway to different legal practices as enacted in different countries, regions or cities. Both merchant and consular courts would be replaced by admiralty courts in the long term, with the consular prevailing significantly longer. Consular courts continued to be used regularly as alternatives to prize courts well into the eighteenth century, mainly due to the practicalities of international jurisdiction. Whatever their origins, the demand for maritime courts was a direct result of international trade and its expansion. Admiralty jurisdiction was to solve this demand by addressing maritime law in a more standardised, regulated and clear fashion.

For many Londoners, the American Revolution had been a conflict far away, to be observed, not actively participated in. But for James Marriott (1730–1803) it was a matter of personal and professional importance. Sir James Marriott was the Judge of the High Court of Admiralty in London from 1778 until his resignation in 1798. The son of a London attorney, he was admitted to the College of Advocates in November 1757 and fulfilled the position of King's Advocate for four years from 1764 to 1768. He resided over the court throughout the course of four different wars, often struggling with the amount of work created by them.

Marriott was or certainly styled himself a zealous patriot and ardent anti- Americanist, both in the field of politics and in international law; for example, describing Britain as a “Nation […] too dazzling not to be seen by some of the Maritime Powers with Malevolence”. According to him, the civilian united the characteristics of “the scholar, the gentleman and friend of their country”. This patriotic flair can also be found in his judgments, such as in one case before the High Court of Admiralty, where he went so far as to say:

That this [British] nation (now fighting for its domestic preservation, as well as empire) had its cruelest enemies within its own bowels [America]; that he [Marriott] would be bound by the act in regard to costs. The American prohibitory act regulated, like other prize acts, the modes of proceeding, but did not take away the general powers of the Court; that the act required bail for double costs from the claimants [Americans]; but there were other costs beside those upon bail.

While Bayard was ostensibly to act as a neutral wartime judge, he had much to gain by aiding the British, and was, in his official capacity, woven into the web of British governmental operations. Indeed, a provenance note regarding a portrait of Robert Bayard's second wife documents that he was not only known as Major Bayard but would later also be known as “the Loyal American” by family descendants. Correspondence can be found in which British military commanders enquired about the status of cases, with Bayard acting as a hub of knowledge, regardless of whether the cases fell into his official jurisdiction. Other correspondence, however, shows a far closer link to the British government, with Major Thomas Murray, the aide-de-camp of William Tryon's successor to the governorship of New York, James Robertson, writing to Bayard, that, “I am directed […] to request that you will give the necessary Orders that the Vessel […] mentioned may not be condemned till the matter is enquired into”. Though it is hard to discern from the lack of context, it appears from this letter that Bayard as the vice-admiralty judge, was receiving orders from officials who definitively expected condemnations before any due process had taken place.

To understand Bayard's role in military operations, it is important to examine his court and the realities faced by claimants facing him.

“The American Revolution was a legal, as well as a political revolution”, is how Erwin C. Surrency, founder of the American Legal History Journal, phrased it. The year 1776 spiralled into a whirlpool of blood, sea salt and independence that not only washed up on the global shores but was knitted into the maritime fabric of the law. The events ripped apart families as it stitched together new ideas and diverging concepts of loyalty. British and ‘patriot’/‘rebel’/American forces clashed not only on land but also at sea. While many consider the ocean a lawless space, maritime and naval warfare had a legal framework on which its players were supposed to base their actions, just as there was on land. This framework was not simply provided by the strategies and policies of politicians and military men, but it was reflected in the courts of law. Americans had no national navy upon the outbreak of hostilities, instead turning to privateering. Privateers were not national naval vessels, but private ships and their crews that had obtained licences to capture enemy vessels. To distinguish them from illegal pirates, they had to follow rules concerning how, when and whom to capture, as well as bringing the captured vessels into ports where the legality of captures was verified. These admiralty or vice-admiralty court processes enabled them to legally receive shares in the ‘prizes’ they had made, making privateering an act of national defence including a financial incentive for the individuals involved. Hulbert states that this “other half of the story – that is, what happened once the prize was brought to port and before a Court of Admiralty – could be just as perilous, uncertain, and complicated as the endeavour to capture an enemy vessel”.

On 1 September 1807 the privateer Betsey (Chant) successfully captured the American merchant vessel Minerva (Caldwell). She had been bound from New York to Amsterdam, laden with sugar, coffee, hides and other articles. The vessel was brought into Plymouth, and, on 29 September, was restored along with all the cargo except 5,839 hides, which were condemned as legal prize. The captors alleged that the hides had been transferred to the Minerva from the Eagle, an American vessel that had purchased them at Monte Video. The owners of the hides disagreed and went on to appeal. The work of the arbitration commission under Article VII had been concluded for three years, thus there was no governmental assistance in the case. Nevertheless, through their merchant connections, the American owners found a way to get British aid: Charles Wall, a partner in the London merchant company Baring, Brothers & Co., appealed the case on their behalf. He took on the case for the New York owners of the goods in question: LeRoy, Bayard and Co. Sadly, the Lords of Appeal did not alter the decree issued by the High Court of Admiralty. LeRoy, Bayard & Co. had to accept the verdict of the British admiralty system.

William Bayard Jr (1761–1826) was a few years older than his distant relative, Samuel Bayard. Unlike his uncle, Robert Bayard, who had been condemning American ‘rebels’ during the War of Independence, or his father, William Bayard Sr, who had fled the country and whose property had largely been confiscated, William Bayard Jr remained in the United States and attained American citizenship. In 1786, he set up the mercantile firm of LeRoy, Bayard & Co. alongside his brother-in-law Herman LeRoy.

Some of the captured sailors from vessels condemned in the Vice-Admiralty Court of New York would have been sent to detention facilities under British control. These men, often from low social backgrounds with no military training, were considered to be regular rebels as opposed to soldiers by the British armed forces, meaning they were not recognised as prisoners of war and thus were not subject to the standards of treatment required for prisoners of war by international agreements. Up to 18,000 Americans died in British captivity during the conflict. When the American Commissary General of Prisoners, Elias Boudinot, signed the preliminary articles of peace in 1783, the British treatment of American prisoners of war was glossed over. It was not conducive to the establishment of peaceful relations and the treaty declared that “all past Misunderstandings and Differences that have unhappily interrupted the good Correspondence and Friendship” between the now independent United States and Britain were to be put aside.

John Jay had been one of the negotiators of the 1783 peace treaty and had, in this capacity, travelled to London. In mid-December 1783, Jay noted that he had met his cousin, William Bayard (Sr), on the street there. Cousin ‘Billy’ was a loyalist, John Jay a patriot civil servant. Loyalists were often looked down upon as “fools and traitors”, their conduct during the war considered worse than that of the British. The different political outlooks and choices that the two cousins had made were, at this point, insurmountable. They passed each other on the street as if they were strangers.