| A | B |
| Thomas Jefferson | made deal to buy Louisiana Territory from France |
| $15 million | price paid for Louisiana Territory |
| Meriwether Lewis and William Clark | hired by Jefferson to explore part of Louisiana Territory |
| Missouri River | river Lewis and Clark traveled |
| Mandan Indians | tribe with whom Lewis and Clark's expedition spent first winter |
| Toussaint Charbonneau | French-Canadian guide; Sacajawea's husband |
| Sacajawea | Shoshone guide and interpreter |
| 2 years | length of Lewis and Clark's expedition |
| Pomp | Sacajawea's son |
| Seaman | Newfoundland dog traveling with the expedition |