| Value | Category |
|---|---|
| 1 | Both parents born in U.S. state |
| 2 | Mother born in U.S. possession |
| 3 | Mother foreign born |
| 4 | Father born in U.S. possession |
| 5 | Father foreign born |
| 6 | Both parents born in U.S. possession |
| 7 | Father born in U.S. possession; mother foreign born |
| 8 | Mother born in U.S. possession; father foreign born |
| 9 | Both parents foreign born |