| 1920 | Alexander B Gilfillan | Head | 42 | Own | White | Married | Pennsylvania | Electric Co. | Solicitor | |
| Lydia E Gilfillan | Wife | 45 | | White | Married | Pennsylvania | | | |
| Alexander Edwin Gilfillan | Son | 13 | | White | Single | Pennsylvania | | | |
| Robert D Gilfillan | Son | 12 | | White | Single | Pennsylvania | | | |
| Mildred E Gilfillan | Daughter | 7 | | White | Single | Pennsylvania | | | |
| 1930 | Alexander B Gilfillan | Head | 52 | Own | White | Married | Pennsylvania | public utility | solicitor | |
| Lydia E Gilfillan | Wife | 53 | | White | Married | Pennsylvania | | | |
| Alexander Edwin Gilfillan | Son | 22 | | White | Single | Pennsylvania | | | |
| Robert D Gilfillan | Son | 22 | | White | Single | Pennsylvania | law firm | statistician | |
| Mildred E Gilfillan | Daughter | 18 | | White | Single | Pennsylvania | | | |