The ‘Atlantic Neptune’ to which this work belongs is one of the greatest hydrographic achievements of the eighteenth century. Undertaken by des Barres he set about providing the British government with more accurate mapping of the entire coastline of America and Canada. Issued from 1777 they proved to be of just as much use to the American Rebel forces. Their quality and accuracy are well known and deserved. The vast majority of the plates issued relate to the north eastern portion of America and Canada, very few were issued of the south. It is presumed that these were later issues, c.1780. As such and because each example of the atlas is different in content, this chart is one of the rarest. ‘Charting Louisiana’ p. 87.