Major Willoughby Morgan was a Commandant at Fort Harrison.
From Fort Harrison on the banks of the Wabash, 1812-1912:
It is known that Major Willoughby Morgan was in command of the Fort December 1815. When he succeeded Captain Taylor [later President Zachary Taylor] or whether there was another officer between them is not known. In about May, 1816, he was ordered to other duty by General Jackson, then Commander- in-Chief of the Army, and left Major John T. Chunn in command of the Fort. It is said that he rebuilt the Fort.
Fort Harrison is described in Wood's English Prairie... . Major Willoughby Morgan enlisted in Virginia, served throughout the War of 1812-15, and at its close was retained as captain of a regular rifle regiment. In 1817 he was promoted to a majoralty, and served continuously in the army until his death, April 4, 1832. [Source]
Major Willoughby Morgan's acceptance of the grade assigned, written 8 June 1815: