[Talisker]

George Washington had a severe case of smallpox in his youth (he had horrible scars due to this) and smallbox often causes sterility, particularly in males.

Thanks, I think you nailed it. Funny how the reporter and the families involved don't mention this (...seems fairly... uhh... significant...).

[wagglebee]

Few people who had cases of smallpox as severe as Washington’s even survived, so it is highly probable that there were long-term effects and sterility is right at the top of the list.

Also, a person of Washington’s social status (and he was VERY conscious of this) would do everything possible to produce a male heir. Martha Custis was twenty-seven when she married George Washington, she had already had four children and had no known medical problems after this, so it is a virtual certainty that she was fertile. The only real logical conclusion is that George Washington was sterile.