▁ ▁Senate ▁Sen ators ▁were ▁elected ▁by ▁the ▁state ▁legisl atures ▁every ▁two ▁years , ▁with ▁one - third ▁beginning ▁new ▁six - year ▁terms ▁with ▁each ▁Congress . ▁Pre ced ing ▁the ▁names ▁in ▁the ▁list ▁below ▁are ▁Senate ▁class ▁numbers , ▁which ▁indicate ▁the ▁cycle ▁of ▁their ▁election . ▁In ▁this ▁Congress , ▁Class ▁ 1 ▁meant ▁their ▁term ▁ended ▁with ▁this ▁Congress , ▁requiring ▁re e lection ▁in ▁ 1 8 5 6 ; ▁Class ▁ 2 ▁meant ▁their ▁term ▁began ▁in ▁the ▁last ▁Congress , ▁requiring ▁re e lection ▁in ▁ 1 8 5 8 ; ▁and ▁Class ▁ 3 ▁meant ▁their ▁term ▁began ▁in ▁this ▁Congress , ▁requiring ▁re e lection ▁in ▁ 1 8 6 0 . ▁Sk ip ▁to ▁House ▁of ▁Representatives , ▁below ▁ ▁Alabama ▁▁ 2 . ▁Clement ▁C . ▁Clay ▁Jr . ▁( D ) ▁ 3 . ▁Benjamin ▁Fitz pat rick ▁( D ), ▁from ▁November ▁ 2 6 , ▁ 1 8 5 5 ▁ ▁Ark ansas ▁▁ 2 . ▁William ▁K . ▁Sebastian ▁( D ) ▁ 3 . ▁Robert ▁W . ▁Johnson ▁( D ) ▁ ▁California ▁▁ 1 . ▁John ▁B . ▁W eller ▁( D ) ▁ 3 . ▁William ▁M . ▁G win ▁( D ), ▁from ▁January ▁ 1 3 , ▁ 1 8 5 7 ▁ ▁Connecticut ▁▁ 1 . ▁Isaac ▁T ou ce y ▁( D ) ▁ 3 . ▁La f ay ette ▁S . ▁F oster ▁( R ) ▁ ▁Del