Ramsay's Essay originated as a long private letter he wrote when he was a ship's surgeon to an aspiring young officer, a midshipman about to be commissioned in 1760. The same material was given a further airing in 1762 to prepare a petty officer for the life he was hoping for as a commissioned officer. The recipient of this second letter was a seaman whose abilities had attracted the attention of Captain Charles Middleton, who advanced him to the command of a small armed vessel with the local rank of lieutenant. As he was a poorly educated man who might soon be expected to hold his own amongst the more polished lieutenants of the wardroom, Ramsay wanted him to have advice tailored to his situation. He explains he could find no book that gave the kind of advice he felt necessary for any young officer, and he therefore had his original letter of 1760, with the additional material of 1762 as an appendix, published anonymously in book form by a London printer in 1765.

Fifteen years later no comparable work on officer-training had appeared in print, while the need for capable officers had become still more urgent in the face of the dangers threatening Britain from her enemies in arms. Middleton, comptroller of the navy from July 1778, was in anxious correspondence with his friend and former shipmate Richard Kempenfelt, now chief of staff in the Channel fleet, as they considered ways to strengthen the navy materially, tactically and morally. Middleton sounded out Ramsay's availability to help with his paper work in 1779; and, with danger in the background and reform in the offing, the times seemed to call for a reissue of his treatise on the duties of sea officers. An improved and extended second edition appeared in February 1780, followed by a third later the same year, and others in translation. The time for anonymity had passed, and the author was declared to be the Reverend James Ramsay, chaplain in his Majesty's navy.

Despite its success the book was long lost to view and its significance overlooked. For many years the Essay was wrongly attributed to Admiral Sir Charles Knowles since the Bodleian Library's copy of the first anonymous edition bore his name on the cover.