When drawing this plan it is likely that Des Barres made use of existing land surveys held by the Offices of the Board of Trade, hence the inclusion of details such as stone quarries, forests, cultivated land and roads.  Des Barres has added soundings in the Matanza River and detailed the hazardous sand banks and barrs which would affect navigation.  He also marks the position of the lighthouse on Anastasia Island. Since the late 16th century a tower or light house at this point had been closely associated with the defence of the settlement of St. Augustine.  From here, the 16th century Spanish lookouts observed any water borne threats to its security including the approach of

English privateers, commanded by Sir Francis Drake, who attacked and burned St. Augustine in 1586.

Prior to the Treaty of Paris in 1763, which ended the French and Indian War and gave Florida and St. Augustine to the British, St Augustine had been under Spanish rule.  When in 1695, King Charles II of Spain issued the first official edict proclaiming that the Spaniards would be "giving liberty to all...men as well as the women...so that by their example and by my liberality others will do the same." St. Augustine was at the forefront of the move to emancipate slaves from British control and, from thereon in, the British from Georgia and the Carolinas, and the Spanish from St. Augustine had been engaged in a series of raids upon each other.  It is significant that to the north of the town of St. Augustine, Des Barres marks Fort Maze which is today better known as Fort Mose, For many years Fort Mose (or Fort Mossy) was rarely mentioned in accounts of St. Augustine’s long and detailed history but is now acknowledged and celebrated as the first free black settlement in the Americas.

In 1740 British General James Oglethorpe, supported by a large colonial militia and Seminole warriors laid siege to St. Augustine in 1740.  He was repulsed by the strong fortifications which protected the town, and the British gave up their efforts to take control of the area until they were granted ownership of Florida through the Treaty of Paris in 1763. Des Barres marks on this plan the location of a battery position used by Oglethorpe on Anastasia Island all those years previously.

Throughout the War of Independence, St. Augustine served as a Loyalist (pro-British) colony for two reasons.  Firstly, the British rather changed their policy with regard to slavery whereby it was now they who were offering ‘freedom’ to the huge slave population as an inducement to support the Loyalist cause.  Secondly, the British brought thousands of English colonists in the city, to counteract the primarily black and mullato population which had developed over many years.