district                           vacator                                 reason for change                       successor           date successor seated
0             maryland 5th                            vacant  rep stephen w gambrill died in previous congress            lansdale sasscer (d)               january 12 , 1943
1             arkansas 4th             william b cravens (d)                            died january 13 , 1939           william f cravens (d)             september 12 , 1939
2         pennsylvania 4th               j burrwood daly (d)                              died march 12 , 1939             john e sheridan (d)               november 7 , 1939
3            tennessee 6th             clarence w turner (d)                              died march 23 , 1939             w wirt courtney (d)                   may 11 , 1939
4            new york 34th                     bert lord (r)                                died may 24 , 1939                edwin a hall (r)               november 7 , 1939
5              georgia 4th                 emmett m owen (d)                               died june 21 , 1939               a sidney camp (d)                 august 1 , 1939
6            wisconsin 3rd              harry w griswold (r)                                died july 4 , 1939  vacant until the next congress  vacant until the next congress
7            tennessee 3rd              sam d mcreynolds (d)                               died july 11 , 1939              estes kefauver (d)             september 13 , 1939
8          california 18th                thomas m eaton (r)                          died september 16 , 1939  vacant until the next congress  vacant until the next congress
9       south carolina 1st             thomas s mcmillan (d)                          died september 29 , 1939            clara g mcmillan (d)               november 7 , 1939
10               ohio 22nd              chester c bolton (r)                            died october 29 , 1939            frances p bolton (r)              february 27 , 1940
11           tennessee 2nd                 j will taylor (r)                           died november 14 , 1939          john jennings , jr (r)              december 30 , 1939
12  puerto rico at - large  santiago iglesias (coalitionist)                            died december 5 , 1939       bolívar pagán (socialist)              december 26 , 1939
13            colorado 3rd                 john a martin (d)                           died december 23 , 1939            william e burney (d)               november 5 , 1940
14            michigan 5th                  carl e mapes (r)                           died december 12 , 1939            bartel j jonkman (r)              february 19 , 1940
15           new york 14th            william i sirovich (d)                           died december 17 , 1939          morris m edelstein (d)               february 6 , 1940
16               ohio 17th            william a ashbrook (d)                             died january 1 , 1940            j harry mcgregor (r)              february 27 , 1940
17            nebraska 1st               george h heinke (r)                             died january 2 , 1940                john h sweet (r)                 april 19 , 1940
18           new york 31st              wallace e pierce (r)                             died january 3 , 1940          clarence e kilburn (r)              february 13 , 1940
19           new york 22nd               edward w curley (d)                             died january 6 , 1940              walter a lynch (d)              february 20 , 1940
20                iowa 6th              cassius c dowell (r)                            died february 4 , 1940            robert k goodwin (r)                  march 5 , 1940
21               maine 2nd                   clyde smith (r)                               died april 8 , 1940        margaret chase smith (r)                   june 3 , 1940
22             georgia 8th              w benjamin gibbs (d)                              died august 7 , 1940      florence reville gibbs (d)                october 1 , 1940
23          new jersey 8th                george n seger (r)                             died august 26 , 1940  vacant until the next congress  vacant until the next congress

Table as JSON:
{"district":{"0":"maryland 5th","1":"arkansas 4th","2":"pennsylvania 4th","3":"tennessee 6th","4":"new york 34th","5":"georgia 4th","6":"wisconsin 3rd","7":"tennessee 3rd","8":"california 18th","9":"south carolina 1st","10":"ohio 22nd","11":"tennessee 2nd","12":"puerto rico at - large","13":"colorado 3rd","14":"michigan 5th","15":"new york 14th","16":"ohio 17th","17":"nebraska 1st","18":"new york 31st","19":"new york 22nd","20":"iowa 6th","21":"maine 2nd","22":"georgia 8th","23":"new jersey 8th"},"vacator":{"0":"vacant","1":"william b cravens (d)","2":"j burrwood daly (d)","3":"clarence w turner (d)","4":"bert lord (r)","5":"emmett m owen (d)","6":"harry w griswold (r)","7":"sam d mcreynolds (d)","8":"thomas m eaton (r)","9":"thomas s mcmillan (d)","10":"chester c bolton (r)","11":"j will taylor (r)","12":"santiago iglesias (coalitionist)","13":"john a martin (d)","14":"carl e mapes (r)","15":"william i sirovich (d)","16":"william a ashbrook (d)","17":"george h heinke (r)","18":"wallace e pierce (r)","19":"edward w curley (d)","20":"cassius c dowell (r)","21":"clyde smith (r)","22":"w benjamin gibbs (d)","23":"george n seger (r)"},"reason for change":{"0":"rep stephen w gambrill died in previous congress","1":"died january 13 , 1939","2":"died march 12 , 1939","3":"died march 23 , 1939","4":"died may 24 , 1939","5":"died june 21 , 1939","6":"died july 4 , 1939","7":"died july 11 , 1939","8":"died september 16 , 1939","9":"died september 29 , 1939","10":"died october 29 , 1939","11":"died november 14 , 1939","12":"died december 5 , 1939","13":"died december 23 , 1939","14":"died december 12 , 1939","15":"died december 17 , 1939","16":"died january 1 , 1940","17":"died january 2 , 1940","18":"died january 3 , 1940","19":"died january 6 , 1940","20":"died february 4 , 1940","21":"died april 8 , 1940","22":"died august 7 , 1940","23":"died august 26 , 1940"},"successor":{"0":"lansdale sasscer (d)","1":"william f cravens (d)","2":"john e sheridan (d)","3":"w wirt courtney (d)","4":"edwin a hall (r)","5":"a sidney camp (d)","6":"vacant until the next congress","7":"estes kefauver (d)","8":"vacant until the next congress","9":"clara g mcmillan (d)","10":"frances p bolton (r)","11":"john jennings , jr (r)","12":"bolívar pagán (socialist)","13":"william e burney (d)","14":"bartel j jonkman (r)","15":"morris m edelstein (d)","16":"j harry mcgregor (r)","17":"john h sweet (r)","18":"clarence e kilburn (r)","19":"walter a lynch (d)","20":"robert k goodwin (r)","21":"margaret chase smith (r)","22":"florence reville gibbs (d)","23":"vacant until the next congress"},"date successor seated":{"0":"january 12 , 1943","1":"september 12 , 1939","2":"november 7 , 1939","3":"may 11 , 1939","4":"november 7 , 1939","5":"august 1 , 1939","6":"vacant until the next congress","7":"september 13 , 1939","8":"vacant until the next congress","9":"november 7 , 1939","10":"february 27 , 1940","11":"december 30 , 1939","12":"december 26 , 1939","13":"november 5 , 1940","14":"february 19 , 1940","15":"february 6 , 1940","16":"february 27 , 1940","17":"april 19 , 1940","18":"february 13 , 1940","19":"february 20 , 1940","20":"march 5 , 1940","21":"june 3 , 1940","22":"october 1 , 1940","23":"vacant until the next congress"}}