Here is the 1850 US Census for my 3rd great grandparents, Hannah (Birge) and Dudley Cass (lines 8 and 9) and my 4th great grandparents Mary "Polly" (Lyford) and Abraham Cass (lines 22 and 23).
The Cass families were living in Oakland, Jefferson County, Wisconsin. I believe this was the first census for them living in Wisconsin, having moved from Canada and New Hampshire via Ohio.
This census states Dudley was born in Canada. Other records have indicated New Hampshire or Vermont. Here is an interesting webpage that addresses the confusion.