From the ever fascinating Flowing Data blog.
I've decided to take the liberty of blowing up the map (somewhat) and showing the close ups provided at the original link. Please click on the attached thumbnails:
Here are some more:
The breakdown on slaveholding patterns is interesting...
I had a book out a while ago that I can't reference at the moment, but IIRC about 1/3 of Southern families owned slaves, but most owned one or two, and few owned more than four or five.
In all the lands of the Confederacy less than one percent of the white population owned 50 or more slaves, and only about 2000 slaveholders owned more than 100 slaves. This latter figure is probably roughly analogous to the number of industrial and financial magnates in the North at the time, which IMO is highly relevant to the economic forces leading to war.
It's also interesting to look at the case of free negroes who owned slaves in the South, like former slave William Ellison, one of the most prolific and ruthless slaveholders in the state of South Carolina and a staunch supporter of the Confederate cause.