 On November 18, 2009, Byrd became the longest-serving member in congressional history, with 56 years, 320 days of combined service in the House and Senate, passing Carl Hayden of Arizona.Previously, Byrd had held the record for the longest unbroken tenure in the Senate (Thurmond resigned during his first term and was re-elected seven months later).He is the only senator ever to serve more than 50 years.