sentences:  Elected as a Whig to the 30th United States Congress to fill the vacancy caused by the death of John M. Holley, Blackmar held the office of United States Representative for the 27th district of New York from December 4, 1848, to March 4, 1849.Afterwards he resumed his former business activities in Newark.Blackmar served again as Town Supervisor from 1852 to 1853.