Carolina in 1757 was in the middle of the French and Indian War worried that the French from the West and in league with the Spanish from the South might push this coastal English colony into the Atlantic. The Huguenots (driven out by Louis XIV in 1685 with the revocation of the Edict of Nantes) especially were worried because the Spaniards viewed them as vermin. (See "Seven years War" in Wikipedia for more detail. The 1757 edition of the DeBrahm shows this precarious situation accurately.
In only 23 years there were amazing changes.
Carolina in 1780 was in the middle of the American Revolution with Yorktown a year away and the treaty of Paris three years away. They are still an English colony but now are wildly enraged by the depredations of Tarleton during numerous engagements. All hopes for rapprochement with the mother country were dashed. Even Bostonians looked tame in comparison.
South Carolina is no longer a sliver of a colony along the coast but now has expanded west up its many rivers into the full width of the state. This watery line of economic success illustrates for the birth of a vastly wealthy planter's class whose domination was completed with the 6 Indian Removal Acts of the 1830's. This map shows the beginning of this brutal story.
Aggressive men found the vision this map provided irresistible for half a century. They became legends.