Railroads impacted corporate America in many ways. First, to start construction of railroads it was needed a huge amount of steel, iron, and coal, this caused the development of new industries in these areas.
Railroads also increased mobility and made able to spread goods around the country which caused the growth of crops business and cattle - which led to big business investing in these areas -.
Also, Railroads companies were the first business to raise funds by issuing stocks and bonds, they were responsible for creating new concepts of management and were the first giant corporations in the US.