state (class)                 vacator                  reason for change               successor date of successors formal installation
0        alabama (2)               new seats  alabama was admitted to the union      john w walker (dr)             elected december 14 , 1819
1        alabama (3)               new seats  alabama was admitted to the union     william r king (dr)             elected december 14 , 1819
2          maine (2)               new seats    maine was admitted to the union         john holmes (f)                 elected june 13 , 1820
3          maine (1)               new seats    maine was admitted to the union      john chandler (dr)                 elected june 14 , 1820
4       maryland (1)  alexander c hanson (f)               died april 23 , 1819    william pinkney (dr)             elected december 21 , 1819
5       virginia (2)       john w eppes (dr)         resigned december 4 , 1819    james pleasants (dr)             elected december 10 , 1819
6  massachusetts (1)     prentiss mellen (f)             resigned may 15 , 1820      elijah h mills (f)                 elected june 12 , 1820
7   rhode island (2)  james burrill , jr (f)            died december 25 , 1820  nehemiah r knight (dr)               elected january 9 , 1821

Table as JSON:
{"state (class)":{"0":"alabama (2)","1":"alabama (3)","2":"maine (2)","3":"maine (1)","4":"maryland (1)","5":"virginia (2)","6":"massachusetts (1)","7":"rhode island (2)"},"vacator":{"0":"new seats","1":"new seats","2":"new seats","3":"new seats","4":"alexander c hanson (f)","5":"john w eppes (dr)","6":"prentiss mellen (f)","7":"james burrill , jr (f)"},"reason for change":{"0":"alabama was admitted to the union","1":"alabama was admitted to the union","2":"maine was admitted to the union","3":"maine was admitted to the union","4":"died april 23 , 1819","5":"resigned december 4 , 1819","6":"resigned may 15 , 1820","7":"died december 25 , 1820"},"successor":{"0":"john w walker (dr)","1":"william r king (dr)","2":"john holmes (f)","3":"john chandler (dr)","4":"william pinkney (dr)","5":"james pleasants (dr)","6":"elijah h mills (f)","7":"nehemiah r knight (dr)"},"date of successors formal installation":{"0":"elected december 14 , 1819","1":"elected december 14 , 1819","2":"elected june 13 , 1820","3":"elected june 14 , 1820","4":"elected december 21 , 1819","5":"elected december 10 , 1819","6":"elected june 12 , 1820","7":"elected january 9 , 1821"}}