The numbers on this drawing show the order in which different sections of the Capitol were built. The dates below are for each section's first construction period and do not include rebuilding or repair.

1. Original north (Senate) wing, 1793-1800
2. Original south (House) wing, 1793-1807
3. Center section and Rotunda, 1818-1824
4. Present House and Senate wings and connecting corridors, 1851-1867
5. Cast-iron dome, 1855-1866
6. Terraces, 1884-1892
7. East front extension, 1958-1962
8. Courtyard infill rooms, 1991-1993