It's not exactly an archaeological example, but it is historically  
documented that slaves were buried in an area beyond the cemetery  
fence at the College Hill Presbyterian Church near Oxford, MS.   The  
church has been restoring access to this area and keeping it mowed and  
cleared of brush.  The church's website has a short bit:

http://www.collegehillpca.com/aboutus/founding.html

I did some research on the cemetery as part of an undergraduate  
project for a mortuary studies class. Unfortunately I'm no longer in  
the Oxford area so I can't easily access the church records.    I  
should note that College Hill was founded as a Presbyterian community  
by a group of settlers who moved into the area en masse in the early  
19th century.  It seems to have been a fairly tight-knit community  
with established customs.  The plantations of the area were modest by  
the standards of coastal South Carolina or the Mississippi Delta, and  
probably meant that the slaves had closer oversight than was the norm  
in areas with larger plantations and wide-spread slave communities.

Jonathan

On Jul 2, 2009, at 12:17 PM, Jane Lee wrote:

> I have a question regarding the burial of slaves that I would like  
> to pose to the
> group. Does anyone know of an archaeological example of slave  
> burials that
> were located immediately outside the perimeter of an established  
> cemetery? I
> have found several historical refences that mention the practice of  
> burying
> slaves near their "masters," but on the outside of the cemetery  
> fence. Anyone
> have any "ground truth" for this practice?