How did the East benefit from interstate railroads in the 1850s

Railroads played a large role in the development of the United States from the industrial revolution in the North-east (1810–1850) to the settlement of the West (1850–1890). The American railroad mania began with the founding of the first passenger and freight line in the nation of the Baltimore and Ohio Railroad in 1827 and the "Laying of the First Stone" ceremonies and beginning of its long construction heading westward over the obstacles of the Appalachian Mountains eastern chain the following year of 1828, and flourished with continuous railway building projects for the next 45 years until the financial Panic of 1873 followed by a major economic depression bankrupted many companies and temporarily stymied and ended growth.

b) brahmans   is nomadic society

answer; (d) i believe that the correct answer is americans finally ran out of ammunition;