That would be Citizen Genet. During the early French Revolution he made himself a pain to the US government by raising troops and privateers to fight the English. This while the USA was trying to stay neutral. After one of the Revolution's government changes he was recalled probably to be executed for his specific political (though still revolutionary) stand. Although he was despised by Washington, Jefferson, and Hamilton among others, Hamilton pushed to have this pain in the butt granted political asylum and he lived out his life in the USA. Lucky guy, but it set a precedent that the USA would grant asylum to people facing execution in their homeland for political beliefs so long as they kept quiet while here.

Follow-up: if true, was this used as a bargaining chip in some way by the Americans?