Hello. I believe his mother, Julia Knox Hull passed in 1842 and his father may have moved to Georgia leaving him to attend a school in Connecticut. He's in the 1850 Census in Derby, New Haven, CT along with one of his sisters and a brother and at least three other members of the
Hull family. Mary Hull [unknown relation to his mother], 59 years of age, is the head of this household in 1850, so its possible these are the relatives on the maternal side of the tree.
Anyway, that's a great photo retouch at the head of this thread! I'm not sure if this has been posted elsewhere but here is Wheeler in motion in 1898, via the Library of Congress collection: