back-skin

I have observed the horses and other animals in the high hilly country of Carolina, Georgia, Virginia and all along our shores, are of a much larger and stronger make, than those which are bred in the flat country next the sea coast; a back-skin of the Upper Creeks and Cherokees will weigh twice as heavy as those of the Siminoles or Lower Creeks, and those bred in the low flat country of Carolina.

Travels Through North & South Carolina, Georgia, East & West Florida, the Cherokee Country, the Extensive Territories of the Muscogulges, or Creek Confederacy, and the Country of the Chactaws; Containing An Account of the Soil and Natural Productions of Those Regions, Together with Observations on the Manners of the Indians. 1823