James Haggerty was a Man of letters.
James was a scholarly man of letters. Along with Peter Jenkins, he powered up the Men of Letters Bunker. He was well-versed with several creatures and dimensions. Also with Jenkins, he was one of two men of letters who Dorothy sought assistance from. However, during their meeting, the Wicked Witch escaped and placed Peter Jenkins under her control. Dorothy, followed by the Wicked Witch, ran up to the lab while Peter attacked James. In the ensuing fight, James stabbed Peter with his own knife, freeing his fellow man of letters from control but also killing him in the process. After Dorothy disappeared, James worked her case every day until he retired, refusing to let it be closed and refusing to give up on her. Though he could never find Dorothy, he was able to find a weakness for the Wicked Witch, poppy extract and he made a deal with a fairy to get some which was later used by the Winchesters, Dorothy and Charlie Bradbury to fight the Witch in 2013.
At some point before his death, he also compiled a thesis titled On the Inner Workings of Angels, indicating he had vast and deep knowledge on celestials, despite the angels not revealing themselves again until the 21st century.