Why do you think president Thomas Jefferson wanted the land beyond the Mississippi river

To expand the lusianna purchase

If you're talking about the Louisiana purchase, there are a couple of reasons. 1) the land was being sold for very cheap (I think it was around 5 cents an acre, but don't quote me on that) and 2) the idea of manifest destiny. Manifest destiny is the idea that the United States should stretch as far west as possible. (Think of it like in the song, America the beautiful: from sea to shining sea) by buying the land east of the Mississippi, Thomas Jefferson could expand the US and gain all of the natural resources on the new land