Senate President pro Tempore Kenneth McKellar served as acting President of the Senate during this "odd" session of the 81st Congress due to a vacancy in the Vice Presidency of the United States until Noon on 20 January 1949 (when Vice President Alben W. Barkley was sworn in for a full four-year term in that office); during this same period, House Speaker Sam Rayburn was next in line to the Presidency under the 1947 Presidential Succession Act.