Final answer:
David Thompson focused on mapping waterways in western Canada and the northwestern United States, whereas the Corps of Discovery, led by Lewis and Clark, aimed to explore and map newly acquired U.S. western territories, establish trade routes, and gather scientific information from 1804 to 1806.
Step-by-step explanation:
The expedition routes of David Thompson and the Corps of Discovery were different in their focus and areas explored. The Corps of Discovery, led by Meriwether Lewis and William Clark, was commissioned by Thomas Jefferson and undertook its journey from 1804 to 1806. Their mission was to explore the new western lands of the United States, map the territory, establish trade routes, and gather scientific information.
On the other hand, David Thompson was a British-Canadian fur trader and explorer who extensively mapped North America, particularly western Canada and the northwestern part of the United States. Thompson's work primarily focused on waterways but did not parallel the journey of the Corps of Discovery. He explored regions around the Columbia River and made significant contributions to the mapping of Canada.
Therefore, the correct comparison and contrast between David Thompson's expeditions and the Corps of Discovery are that David Thompson explored the western coast and mapped waterways in Canada, whereas the Corps of Discovery focused on mapping the newly acquired western territories of the United States, including the Missouri River and the Pacific Northwest. From their respective travels, both contributed valuable geographical and scientific data, although their primary objectives and areas of exploration differed.