Mallary was elected trustee of the Rutland County Grammar School in 1807. He was appointed by Governor Israel Smith as Secretary to the Governor and Council in 1807, he held that position again from 1809 to 1812 and from 1815 to 1819.[2] He served as the State's attorney for Rutland County from 1811 to 1813.[3] In 1816, Mallary moved to Poultney, Vermont. He was defeated for Congress in 1819 because votes for several of the towns were not returned early enough to be counted. As a Democratic-Republican, Mallary successfully contested the election of Orsamus C. Merrill to the Sixteenth Congress.[4]
Graffagnino, J. Kevin. "'I saw the ruin all around' and 'A comical spot you may depend': Orasmus C. Merrill, Rollin C. Mallary, and the Disputed Congressional Election of 1818." Vermont History 49 (Summer 1981): 159-68.