In the case of Monessen Southwestern Railway Co. v. Morgan, the U.S. Supreme Court ruled that a railroad worker could not recover damages for emotional distress under the Federal Employers' Liability Act (FELA) unless he also suffered a physical injury. The plaintiff, Morgan, was an employee of Monessen Southwestern Railway who claimed to have developed post-traumatic stress disorder after witnessing several fatal accidents at work over his 30-year career with no physical injuries involved in these incidents. He sued his employer under FELA seeking compensation for emotional distress and lost wages due to his inability to continue working because of this condition. The court held that while FELA is intended to provide broad protection for railway workers, it does not extend so far as allowing recovery for purely psychological harm without any accompanying physical injury or impact on one's ability to perform their job duties effectively. This decision has had significant implications regarding what types of damages are recoverable under federal law in workplace accident cases.

In the dissenting opinion for Monessen Southwestern Railway Co. v. Morgan, Justice Brennan argued that the majority's decision was inconsistent with both congressional intent and previous court rulings regarding the Federal Employers' Liability Act (FELA). He contended that Congress intended to allow recovery for emotional distress under FELA, as it is a common law right in negligence cases. Furthermore, he pointed out that courts have previously allowed such damages in FELA cases without requiring physical injury or impact. According to him, this ruling unnecessarily restricts workers' rights and protections under FELA by limiting their ability to recover damages for emotional distress caused by employer negligence.