For those interested in the "salacious" stories about GW, I have a chapter
in my book "An Imperfect God" about West Ford, said to be GW's son by a
slave named Venus. The chapter is called "A Sort of Shadowy Life" (a quote
from Faulkner).  Just this weekend after a talk in Richmond I had a
discussion with a GW relation who told me with total certainty that GW could
not have had any children because of his smallpox episode. One often hears
this; I looked into it while researching the book, and spoke with a
historian of smallpox. She pointed me to the only modern epidemiological
study of this question, which found no correlation between smallpox and male
infertility. One doctor has speculated that GW's serious bout with a form of
tuberculosis may have left him unable to father children, and other medical
theories have been raised. It is possible that GW was sterile; it is also
possible that Martha Washington became unable to conceive after her previous
pregnancies. It happens. It's called secondary infertility, I believe. 

Henry Wiencek
Charlottesville