[['state (class)', 'vacator', 'reason for change', 'successor', 'date of successors formal installation'], ['new hampshire (2)', 'vacant', 'legislature failed to elect on time', 'john parker hale (r)', 'july 30 , 1855'], ['alabama (3)', 'vacant', 'legislature failed to elect on time', 'benjamin fitzpatrick (d)', 'november 26 , 1855'], ['pennsylvania (3)', 'vacant', 'legislature failed to elect on time', 'william bigler (d)', 'january 14 , 1856'], ['california (3)', 'vacant', 'legislature failed to elect on time', 'william m gwin (d)', 'january 13 , 1857'], ['indiana (3)', 'vacant', 'legislature failed to elect on time', 'graham n fitch (d)', 'february 4 , 1857']]
William M Gwin and Graham N Fitch joined Congress in 1857
[ENT] and [ENT] joined [ENT] in [ENT]