Final answer:
Meriwether Lewis and William Clark succeeded where La Salle had failed in his expedition. They were selected by Thomas Jefferson to lead an expedition to the new western lands to discover the commercial possibilities and potential trade routes.
Step-by-step explanation:
The 2 people who succeeded where La Salle had failed in his expedition were Meriwether Lewis and William Clark.
In 1804, they were selected by Thomas Jefferson to lead an expedition to the new western lands to discover the commercial possibilities and potential trade routes.
They explored the West from 1804 to 1806, bringing back valuable information on the Indians, geography, and flora and fauna of the areas they explored.