Richardson earned 209 votes to be elected as member for Wolseley (in present-day Saskatchewan) in 1888. He campaigned again and lost in the 1891 Northwest Territories general election, earning 213 votes, while his opponent, James Dill, earned 312. Richardson ran a third time for election in Grenfell in the 1898 Northwest Territories general election, earning 153 votes, while his opponent, Richard Stuart Lake, earned 351. Five general elections would occur between 1888 and 1905, as the territories underwent significant growth. As an assembly member, Richardson was twice appointed to the Advisory Council of Lieutenant Governor Joseph Royal. He also served on its Education, Irrigation, Municipal, and Prairie and Forest Fires committees, among others. Samples of his correspondence with Lieutenant Governor Edgar Dewdney are housed in the archives of the Glenbow Museum in Calgary (Alberta).