Conversation so far:
was New York an evacuation?
to arrange for the implementation of those parts of the Treaty of Paris relating to the evacuation of New York City.
was this a success?
Carleton refused to deliver over the human property to the Americans at the time of the British evacuation.
What was his role?
New York City, then commanded by Carleton.

Question: what did he do in that role?
Self-contained rewrite: What did Carleton do?