There was no other way to get to the New World as any land bridge no long existed.
From Europe the Atlantic Ocean was the route used.
Sailing from Europe to South America, the most practical route would be across the Atlantic Ocean.
to explore the Mississippi river and a route to the Pacific ocean
Middle Passage
The sea route and the land route were generally the same length in time (the Panama canal was not yet dug, forcing ships to go around the Southern tip of South America) and most decided the land route was preferable.
North America
The purpose of the Lewis and Clark expedition, or Corps of Discovery , was to find a water route to the Pacific Ocean.
what route did the settlers take going west of the appalachian mountains
Atlantic Ocean
he was trying to find a new route to the indies
The Pacific would be the only direct route.
It was the middle part of the triangular trade route.