To add my two cents worth of random observations and questions:
 
First, I can't think of a single example of a rural privy on 17th-mid-19th
century sites in SC. I think that the nearby woods were used. Chamber pots
are not unheard of on rural sites, but are by no means common. Privies are
common in the city of Charleston during this period, however. The sort of
privies hanging out over small streams and hillslopes described by many
respondents from the southeast are common in the SC piedmont too. But since
they can only be identified when the structure is still standing we must
assume that they aren't very old.
 
Second, Kenneth Lewis wrote an excellent report on the excavation of a privy
at Middleton Place plantation. This feature was built in the 1880's and
abandoned afer the turn of the century if I remember correctly.  A  typically
excellent report by Lewis and Helen Haskell is available from the SC Inst. of
Archaeology, at the Univ. of SC, (803-777-8170).
 
Third, How does everyone define the concept of  the chamber pot? Those
Westerwald and creamware vessels of the 18th century with flat wide rims and
bowl like bodies with a single handle (as illustrated in Noel Hume page 281)
are what I envision, but what did earlier ones look like? How do they differ
from cream risers and butter pots, which also had wide flat rims? If you only
have a rim, how can you tell, definitively that a vessel was a chamber pot?
Could this be the reason for chamber ware being underreported on earlier
sites? (see #6 also)
 
Fourth, speaking of  classic chamber pots at least one domestic potter,
Anthony Duche of Philadelphia, was making salt glazed stoneware chamber pots
that were, while not identical, extremely good imitations of westerwald
chamberware of the same period.
 
Fifth, which reminds me that Betty Cosans excavated numerous 18th century
privies at Franklin Court in Philadelphia (many of which had been filled with
kiln wasters).  She cited a city ordinance of the 1730's which dictated the
depth and placement of privies (they could not extend into the aquifer used
for drinking water, nor could they be too close to wells).
 
Sixth, In excavations at Santa Elena, a Spanish town on the SC coast dating
between 1565 and 1586, a single vessel identified as a chamber pot was found.
As I recall this vessel is about 18" tall, and flares from a basal diameter
of about 8" to a rim diameter of about a foot. It is more like what I would
consider a cream riser or umbrella stand than a chamber pot. I assume Stanley
South knows what he is talking about, but has any one else seen 16th century
chamber ware?
 
 
Carl Steen