On March 20, 1894, Gardner was appointed Michigan Secretary of State by Governor John T. Rich to fill the vacancy caused by the removal of John W. Jochim. He was then twice elected to the position in 1894 and 1896, serving until 1899. In 1898, he defeated incumbent Democrat Albert M. Todd to be elected as a Republican from Michigan's 3rd congressional district to the 56th United States Congress.
Gardner was appointed Michigan Secretary of State by Governor John T. Rich on March 20, 1894, after Jochim's departure. He won two elections in 1894 and 1896, serving until 1899. In 1898, he defeated Democrat Albert M. Todd to become a Republican representative from Michigan's 3rd congressional district in the 56th United States Congress.