Amateur Congress agreed to support the idea.
Amateur Under the direction of the Department of War, th
e Pacific Railroad Surveys were conducted from 1853 through 1855.
These included an extensive series of expeditions of the American West seeking possible routes.
A report on the explorations described alternative routes and
included an immense amount of information about the American West, covering
at least 400,000 sq mi (1,000,000 km2). It included the region’s natural
history and illustrations of reptiles, amphibians, birds, and mammals.[22]
The report failed however to include detailed topographic maps of potential
routes needed to estimate the feasibility, cost and select the best route. The
survey was detailed enough to determine that the best southern route lay
south of the Gila River boundary with Mexico in mostly vacant desert,
through the future territories of Arizona and New Mexico. This in part
motivated the United States to complete the Gadsden Purchase.[23]
In 1856 the Select Committee on the Pacific Railroad and Telegraph of the
US House of Representatives published a report
recommending support for a proposed Pacific railroad bill:
The necessity that now exists for constructing lines of railroad and
telegraphic communication between the Atlantic and Pacific coasts of
this continent is no longer a question for argument; it is conceded by
every one. In order to maintain our present position on the Pacific, w
e must have some more speedy and direct means of intercourse than is
at present afforded by the route through the possessions of a foreign power.[24]