Art,
He was with Banks when he came through Mansura. The Yankees seem to have had more free-lancing, non-1st Scouts Bn. guides than I'd realized. Dupont's brother was one of the men executed in the mass execution that you're familiar with, and Dupont came into Mansura looking for revenge against Victor Prostdame, the man who turned them in. He couldn't find Prostdame, who was down at Lake Pearl, so got his revenge by burning down what he thought was his house (everyone called it the Prostdame property) but it turned out to be the house (and rum distillery) of Sydonie Pierret. I get the impression from what I read that her place was the place in Mansura where the CS high brass would go to party (also mentioned in Grisamore and Poche?).
This info comes from the French-American Claims Commission case, Ferole Regard vs US.