The first 'official Census of the Dominion of Canada was taken in 1871.
The Library and Archives Canada holds an extensive collection of Canadian census records many of which have been digitized.
You will find Oxford data was collected under River Philip Sub District in the 1871 census.
To search the 1871 Census and learn more about it:
This excerpt from page 30 of the 1871 Census for Nova Scotia, District Cumberland,
Sub District River Philip provides information on several Oxford residents.