 In November 1854, Hall was elected on the Whig ticket to succeed Shepard, and served his first term as New York County District Attorney from 1855 to 1857.He was not re-elected partly due to his unpopularity following the Burdell-Cunningham murder trial.As a Republican, Hall was elected again as the New York County District Attorney in November 1861, and re-elected as a Democratic Tammany Hall candidate in 1864 and 1867.