Norris C. Rockwell (b. 1830), of Adams Co., Ill., and Nodaway Co., Missouri (U7 in the first edition, U17 in the second):

I'm happy to say that, with the third edition, Norris Rockwell will no longer be among the "unplaced" Rockwells. I am now confident that he is indeed the son of George Elwood Rockwell, who also lived in Adams County, Illinois. See his father's page at R218