Calvin was a member of the Conservative Party from 1868 through 1883. Calvin held a number of roles in the Provincial Parliament. He was a member of the Standing Committee on Private Bills (1879–1883), member of the Committee on Railways (1869–1883), member of the Select Committee Appointed to Inquire into the working of the Tavern and License Act of 1868 etc. (1874), member of the Select Committee to enquire into the usefulness and cost of wooden railways as a mean of furthering the settlement of the country (1869), member of the Standing Committee on Privileges an Elections (1869) and member of the Select Committee to consider Bill 58 (An Act regulating Line Fences and Watercourse) (1968).