In 1804-06 it was first
United States overland expedition to the Pacific coast and back. It was conducted under the leadership of Captain
Meriwether Lewis and Lieutenant [William Clark]
?, with the intention of solidifying the
United States claim on the [Lousiana Purchase]
? and the [Pacific Northwest]
?.
The journals of the Lewis & Clark expedition can be seen online at
http://xroads.virginia.edu/~HYPER/JOURNALS/journals.html