state (class)              vacator                          reason for change                successor date of successors formal installation
0         delaware (1)  george r riddle (d)                       died march 29 , 1867  james a bayard , jr (d)                         april 5 , 1867
1         arkansas (2)               vacant        arkansas re - admitted to the union   alexander mcdonald (r)                         june 22 , 1868
2         arkansas (3)               vacant        arkansas re - admitted to the union      benjamin f rice (r)                         june 23 , 1868
3          florida (3)               vacant         florida re - admitted to the union      thomas w osborn (r)                         june 25 , 1868
4        louisiana (2)               vacant       louisiana re - admitted to the union        john s harris (r)                          july 8 , 1868
5        louisiana (3)               vacant       louisiana re - admitted to the union    william p kellogg (r)                          july 9 , 1868
6          alabama (2)               vacant         alabama re - admitted to the union       willard warner (r)                         july 13 , 1868
7          alabama (3)               vacant         alabama re - admitted to the union     george e spencer (r)                         july 13 , 1868
8         maryland (1)  reverdy johnson (d)                    resigned july 10 , 1868      william p whyte (d)                         july 13 , 1868
9   north carolina (2)               vacant  north carolina re - admitted to the union      joseph c abbott (r)                         july 14 , 1868
10  north carolina (3)               vacant  north carolina re - admitted to the union            john pool (r)                         july 14 , 1868
11  south carolina (2)               vacant  south carolina re - admitted to the union   thomas j robertson (r)                         july 15 , 1868
12  south carolina (3)               vacant  south carolina re - admitted to the union   frederick a sawyer (r)                         july 16 , 1868

Table as JSON:
{"state (class)":{"0":"delaware (1)","1":"arkansas (2)","2":"arkansas (3)","3":"florida (3)","4":"louisiana (2)","5":"louisiana (3)","6":"alabama (2)","7":"alabama (3)","8":"maryland (1)","9":"north carolina (2)","10":"north carolina (3)","11":"south carolina (2)","12":"south carolina (3)"},"vacator":{"0":"george r riddle (d)","1":"vacant","2":"vacant","3":"vacant","4":"vacant","5":"vacant","6":"vacant","7":"vacant","8":"reverdy johnson (d)","9":"vacant","10":"vacant","11":"vacant","12":"vacant"},"reason for change":{"0":"died march 29 , 1867","1":"arkansas re - admitted to the union","2":"arkansas re - admitted to the union","3":"florida re - admitted to the union","4":"louisiana re - admitted to the union","5":"louisiana re - admitted to the union","6":"alabama re - admitted to the union","7":"alabama re - admitted to the union","8":"resigned july 10 , 1868","9":"north carolina re - admitted to the union","10":"north carolina re - admitted to the union","11":"south carolina re - admitted to the union","12":"south carolina re - admitted to the union"},"successor":{"0":"james a bayard , jr (d)","1":"alexander mcdonald (r)","2":"benjamin f rice (r)","3":"thomas w osborn (r)","4":"john s harris (r)","5":"william p kellogg (r)","6":"willard warner (r)","7":"george e spencer (r)","8":"william p whyte (d)","9":"joseph c abbott (r)","10":"john pool (r)","11":"thomas j robertson (r)","12":"frederick a sawyer (r)"},"date of successors formal installation":{"0":"april 5 , 1867","1":"june 22 , 1868","2":"june 23 , 1868","3":"june 25 , 1868","4":"july 8 , 1868","5":"july 9 , 1868","6":"july 13 , 1868","7":"july 13 , 1868","8":"july 13 , 1868","9":"july 14 , 1868","10":"july 14 , 1868","11":"july 15 , 1868","12":"july 16 , 1868"}}