These are the only 20th century cardboard puzzles that I have actively tried to collect. Some observations from my incomplete set.
| 1 | untitled (American Sailing Ship) |
| 2 | Deauville Races 1932 |
| 3 | Boat Race |
| 4 | The Prairie Fire |
| 5 | King Arthur's Country |
| 6 | Little Birds of the Shore |
| 7 | Sheridan's Charge |
| 8 | Thanksgiving |
| 9 | Buffalo Hunt |
| 10 | The Jolly Flat Boatmen |
| 11 | Green Sleeves Leads the Way |
| 12 | Winter** |
| 13 | Dogs |
| 14 | Sunset |
| 15 | Wild Horses |
| 16 | Between two Fires |
| 17 | Milady of the Tavern |
| 18 | Charging Elephants |
| 19 | Merchant Ship |
| 20 | Washington at Mt. Vernon |
| 21 | Pickett's Charge at Gettysburg |
| 22 | Boyhood of Sir Walter Raleigh |
| 23 | Hunters |
| 24 | Important Question |
| 25 | So Near Yet So Far |
| 26 | The Defense |
| 27 | A Quiet Battle |
| 28 | Sunday Morning in Norway |
| 29 | The Fortune Teller |
| 30 | Acrobats |
| 31 | Dance of the Minuet |