Notes on the Population Charts
These numbers are all from a site at the University of Virginia's Fisher Libary, here. It'll take some clicking around to get the hang of how it works, but there is an awesome amount of raw data here. If this kind of thing is of interest to you, we recommend it.
On our charts, notice that a lot of Campbell County's decrease, is the splitting off of Kenton County, telling us that Campbell didn't have near the number of slaves that Kenton did.
We assume the dramatic drop in slave percentages in Kenton, Campbell and Mason are traceable to increases in the non-slave population.
We also note the river counties have a gradual decrease in slavery, while Owen and Grant have an increase or a flat line. An underground railroad issue?