1891 census Winnipeg Manitoba
N Stevenson, 26, lodger, b Ontario, both parents b Scotland, Salvation Army, blacksmith.
He is lodging with Thomas & Sarah Walker.
Don't know if this is your Noah or not.
1901 census Norfolk, MacDonald, Manitoba
David Stevenson, 28 Oct 1858, Ontario, farmer.
Elisibeth, 27, Ont
James W, 1898, Manitoba
Nellie M, 1900, Manitoba
They are still there on 1911 census.
Aaron is 10 on 1871 census, not 1.
1881 census Scarborough, Aaron and Noah are still with mother Sarah,father Andrew plus siblings. Aaron is a blacksmith.
James Gray Stevenson, 30, b Markham, living Scarborough, blacksmith, s/o Andrew Stevenson & Sarah Gray, married Margaret Mann, 21, b and living Scarboro, d/o John Mann& Mary Crummins, witn: Elizabeth Thompson of Scarboro, 24 Dec 1881 at Agincourt, Registration # 012931.
I don't see any marriages for any of the children of Andrew and Sarah or deaths either on ancestry.ca. Did they all move to the US with brother James?
I don't have any access to US records but Ancestry.com does have a 14 day free trial.
Don't see any of them on Border Crossings.