John McDougall was born in Prince Edward Island, then part of British North America.
At the age of twenty he left his home and emigrated to the United States where he lived in Maine, Massachusetts and in Minneapolis before he settled in Britton, South Dakota.
Mainly he was engaged in agricultural pursuits and he owned a large stock farm of four hundred acres which he managed.
The Political Graveyard also states he was a lawyer, however this remains unclear because it is not verified in other sources.
In the years 1901 and 1902 he was a member of the South Dakota House of Representatives and from 1903 to 1904 he held a seat in the State Senate.