Barbara Mikulski
Maryland Democratic Sen. Barbara Mikulski, the longest-serving woman in congressional history, will not seek re-election in 2016, according to the Associated Press and The Washington Post. First elected in 1986, she was the first woman to chair the Senate Appropriations Committee, a position she lost when Republicans took control of the chamber following the 2014 elections. Before her election to the Senate, Mikulski served five terms in the House. Ref. CNN