He served in the Legislative Assembly of Manitoba as a member of the Conservative Party from 1903 to 1915, and was a cabinet minister in the government of Rodmond Roblin.
Howden ran to replace the late Conservative cabinet minister John Andrew Davidson and was elected without opposition.
He was re-elected over Liberal Alexander Dunlop by 112 votes in the 1907 election, and was named to cabinet on March 16, 1907 as Railway Commissioner.
The Roblin administration was forced to resign in early 1915, after a commission of enquiry established by the Lieutenant Governor concluded that the government was guilty of corruption in the tendering of contracts for new legislative buildings.
[4] The commission report concluded that Roblin, Attorney General James H. Howden and developer Thomas Kelly had conspired to commit fraud in the contract arrangements.