 National Geographic Historical Atlas of the United States, 6th edition 1917-1929: Headlong into the roaring twenties (PDF) |
 1930-1939: Headfirst into the busted thirties (PDF) |
| National Geographic Historical Atlas of the United States, 6th edition1917-1929: Headlong into the roaring twenties (PDF) |
| 1930-1939: Headfirst into the busted thirties (PDF) |