Lyndon Baines Johnson, often referred to by the initials LBJ, was an American politician who served as the 36th presidentβ ofβ theβ Unitedβ States from 1963 to 1969. Formerly the 37th viceβ president from 1961 to 1963, he assumed the presidency following the assassinationβ ofβ Presidentβ Johnβ F.β Kennedy. A Democrat from Texas, Johnson also served as a Unitedβ Statesβ Representative and as the Majorityβ Leader in the Unitedβ Statesβ Senate.