In the Confederate lexicon both words mean the same thing, with one expression "property in slaves" saying it all.
Yup, the Constitution of the Confederacy is covered over with the linguistic appurtenances of human bondage (to be polite about it).
"Our new government is founded upon exactly the opposite idea; its foundations are laid, its corner- stone rests, upon the great truth that the negro is not equal to the white man; that slavery subordination to the superior race is his natural and normal condition."
Vice President of the Confederacy, Alexander Hamilton Stephens.