state (class)                 vacator                    reason for change                 successor date of successors formal installation
0  south carolina (3)     olin d johnston (d)                 died april 18 , 1965      donald s russell (d)                        april 22 , 1965
1  south carolina (3)    donald s russell (d)  successor elected november 8 , 1965       ernest hollings (d)                      november 9 , 1965
2        virginia (1)        harry f byrd (d)          resigned november 10 , 1965     harry f byrd , jr (d)                     november 12 , 1965
3        michigan (2)  patrick v mcnamara (d)                 died april 30 , 1966      robert p griffin (r)                          may 11 , 1966
4        virginia (2)  a willis robertson (d)          resigned december 30 , 1966  william b spong , jr (d)                     december 31 , 1966

Table as JSON:
{"state (class)":{"0":"south carolina (3)","1":"south carolina (3)","2":"virginia (1)","3":"michigan (2)","4":"virginia (2)"},"vacator":{"0":"olin d johnston (d)","1":"donald s russell (d)","2":"harry f byrd (d)","3":"patrick v mcnamara (d)","4":"a willis robertson (d)"},"reason for change":{"0":"died april 18 , 1965","1":"successor elected november 8 , 1965","2":"resigned november 10 , 1965","3":"died april 30 , 1966","4":"resigned december 30 , 1966"},"successor":{"0":"donald s russell (d)","1":"ernest hollings (d)","2":"harry f byrd , jr (d)","3":"robert p griffin (r)","4":"william b spong , jr (d)"},"date of successors formal installation":{"0":"april 22 , 1965","1":"november 9 , 1965","2":"november 12 , 1965","3":"may 11 , 1966","4":"december 31 , 1966"}}