Le Scaramouche -

Was buggery a capital crime in the USA?

At times and in some places, officially yes.

At times and in more places, effectively yes if you include lynchings as "officially sanctioned" punishments, which they have been in some parts of the country.

"Buggery" is not mentioned in most US (States) law. The usual term is the more general and less specific "sodomy," which remains only vaguely defined in the laws of most states. Until recently several states merely prohibited, sometimes with EXTREME penalties "the unspeakable act," leaving it to the imagination of jurists and juries what might constitute "the crime."

John