He served in the Legislative Assembly of Manitoba from 1914 to 1922, and was a cabinet minister in the government of Tobias Norris.
Grierson received a teaching certificate and served as principal of the Minnedosa public school from 1887 to 1890 and from 1892 to 1902.
[1] Early in 1915, the Conservatives were forced to resign from office in the wake of a serious corruption scandal.
The Liberals won a landslide majority government in the election which followed,[5] with Grierson defeating Conservative candidate[4] James Muir by 219 votes.
[4] The Liberals were reduced to a minority government in the 1920 provincial election,[6] amid the rise of organized Farmer and Labour groups.