Thomas Jefferson imagined that what is now the continental United States would consist of three independent nations: from the Atlantic to the Mississippi River, from the Mississippi River to the Rocky Mountains and from the Rocky Mountains to the Pacific.
Well, of course, he did. When Jefferson died, railroads and electrical telegraphy were in their infancy. Almost all of the United States was a wilderness. Traversing, let along communicating across the vast continent was a monumental task.
In his 1932 Atlas of the Historical Geography of the United States, the distinguished historian Charles O. Paullin showed how long it took to travel across the country from New York City. Look through his maps for 1800, 1830, 1857 and 1930.