District of Columbia Territory
1850 Counties
| County | Description | Area in sq miles | Courts held at | Pop in 1850 |
| Alexandria Co, VA | formerly comprised the part of SC west of Potomac river | 36 | Alexandria | 10,008 |
| Washington | in DC, Potomac river on southwest | 64 | Washington DC | 51,687 |
1850 Towns
| Name | What | County | Pop | Other |
| Anacostia | PO | Washington Co, DC | ||
| Alexandria | City | Alexandria Co, DC | 8,734 | seat of justice, PE Theological Seminary, water by Potomac river |
| Georgetown | City | Washington Co, DC | 8,366 | Roman College |
| Tenallytown | PO | Washington Co, DC | ||