He served on Innisfail's first town council, and also in the legislative assemblies of the Northwest Territories and later Alberta; in the last, he acted as deputy speaker.

Shortly after, he moved to the Olds area, and in 1891 he settled in Innisfail where he started a lumberyard the next year.

He defeated two candidates, including incumbent Francis Wilkins, and was subsequently re-elected in the 1898 and 1902 elections, on the latter occasion in the new district of Innisfail.

During the Alberta and Great Waterways Railway scandal, he remained loyal to the government of Premier Alexander Cameron Rutherford in the face of a rebellion from Liberal insurgents.

There was some concern on the government side that the speaker, Charles W. Fisher, would resign to support the insurgents; Simpson's elevation to speaker, a position which was expected to remain impartial, would rob the government of a crucial vote.