| Answer | Crossword Clue |
|---|---|
| BOONE | U. S. pioneer |
| BOONE | U.S. pioneer. |
| BOONE | U.S. pioneer |
| TESLA | U.S. electrical pioneer |
| OLDS | U.S. auto pioneer |
| LAHM | U.S. balloon pioneer |
| FWWOOLWORTH | U.S. chain-store pioneer |
| MORSE | U.S. artist and telegraphy pioneer |
| SLATER | Pioneer in U.S. cotton industry |
| BEERS | U. S. pioneer in mental hygiene |
| OREGONTRAIL | Great pioneer route of U. S. history. |
| BOONE | Pioneer who lent his name to six U.S. counties |
| TESLA | Electrical pioneer whose last known U.S. patent was for a helicopter-plane |
