Given the possible threat represented by the British Royal Navy to the maritime commerce of the Spanish colonies, Spain took an officially neutral position in the American War of Independence. However, having lost Florida under the terms of the Treaty of Paris (1763) which ended the Seven Years' War, the American Revolution provided a potential opportunity to regain lost territory, or at least a measure of revenge. Diego José Navarro García de Valladares, Governor of Cuba, sent Miralles as an observer to the Continentals in the then capital of Philadelphia. He arrived from Havana early in 1778, allegedly having been on his way to Spain when some problem with the ship forced him to put in at Charleston, South Carolina. Miralles met Washington at a Christmas party and presented a letter of introduction from Navarro. Privateer John Macpherson leased his Mount Pleasant mansion to Miralles. Also while in Philadelphia, Miralles became affiliated with the prominent shipping-banking firm of Willing, Morris & Co.
