This paper chose to focus on the industry of freight railroad corporations in the United States because of their particular relevance in the age of online shopping and their steady performance during & after the pandemic. This paper introduces the basics of the United States freight railroad and the moat of this industry. The freight transportation industry covaries strongly with the overall economy, showing stable long-run growth potential and a relatively low risk. The second half of the paper analyzed the stocks of Union Pacific, CSX and Norfolk Southern via key performances index, including current ratio, earning per share, return on equity, etc. Using Union Pacific as an example, this paper calculated the Weight Average Cost of Capital (WACC) by applying the Capital Asset Pricing Model. Overall, freight railroad companies are a good choice to be a part of investment portfolio for its stable return and low risk.