Following the war of 1812, the construction of us railroads and growth of us cities showed that
the economy was growing quickly.
the united states had won the war.
great britain had lost the war.
the economy only grew in cities.

Following the War of 1812, the construction of US railroads and growth of US cities showed that A) The economy was growing quickly

Explanation:

The War of 1812 brought industrial revolution as the country realised their need to manufacture their goods and to improve their economic condition. The railroads were constructed all over the country to bring forth better transportation.

Production grew exponentially and the change was seen all over the country including the urban and rural sectors. Technology increased the means of agricultural produce which also led to an increase in population and death rate also decreased.

The points of United States winning the war or Britain losing the war aren't relevant and cannot be assumed just because of railroad constructions or growth. Also, economy grew throughout the country rather than just in the cities.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain