Ongoing challenges for U.S. security agencies include determining what methods of terrorism may be deployed post-9/11 to execute attacks, determining security management improvements or changes implemented in order to advance overall safety, and determining what security management improvements or changes should still be made. The purpose of this study was to explore these challenges specifically within the U.S. freight railroad system. Based in systems theory, the holistic case study examined the question if broad and unrestricted methods still exist by which terrorists can strike the railroad system. Following a participant observation model proposed by Yin, coding of direct observations and inspection of physical artifacts, documents, and legislation were aligned to three priority themes within the main research question. Data were then linked into an explanatory cause/effect model which suggested that multiple factors related to freight railroading make it a high potential target for terrorism. The study contributes to social change by identifying terrorism vulnerability risks, promote security improvements, and advance the overall efficacy of security operations within the U.S. freight railroad system.