Following is a possibility:
1860 Henry County, MO, Grand River Twp., July 11
Living in George H. Hardy household (#571-571) 1860
William Robinson 32; NY merchant
John P. Robinson 8; NY
[Heritage Quest]
John's age isn't quite right and he's listed as born in NY instead of MO, but someone else in the household may have talked to the census taker and simply guessed at the information.
~*~
1850 Henry County, MO, Grand River Twp.
B. W. Robinson 22; NY
https://familysearch.org/pal:/MM9.1.1/MDZC-3GG