His letter would be lengthy in its content but without the flowery repose of someone simply ending a relation. It would explain why he could not continue on with his position in the House as the Union doctrine was so different than his own. It explains how he long believed the sovereign states had a right to follow their own doctrines and that although he loved the Constitution, forefathers, etc., he did not believe that it was being followed as it was written.
His letter would be authoritative yet respectful, without malice, contrition, or excuses.