Max Baucus
Baucus announced on April 23, 2013 that he would retire from the U.S. Senate at the end of his term. His term was set to end in 2015. However, he was made United States Ambassador to China by Barack Obama in 2013. He resigned on February 6, 2014, before finishing his final term as senator. Baucus was succeeded by John Walsh, the former Lieutenant Governor of Montana.