In the 1956 case of Ferguson v. Moore-McCormack Lines, Inc., the U.S Supreme Court ruled on a matter involving maritime law and workers' compensation. The plaintiff, Mr. Ferguson, was an employee of Moore-McCormack Lines who suffered injuries while working aboard one of their ships in New York Harbor. He sought damages under the Jones Act which provides for recovery by seamen from their employers for negligence causing injury or death during employment at sea. The issue before the court was whether he could also claim benefits under Pennsylvania's Workmen's Compensation Law where his employer had its principal place of business and where he resided and signed his contract with them. The Supreme Court held that state workmen’s compensation laws cannot be applied to maritime injuries covered by federal legislation such as the Jones Act because it would undermine uniformity in this area of law across states - a key principle underlying maritime jurisdiction.

In the dissenting opinion for Ferguson v. Moore-McCormack Lines, Inc., Justice Frankfurter argued that the majority had overstepped its bounds by interpreting a statute in a way not intended by Congress. He contended that it was not within the Court's power to extend statutory benefits beyond what was explicitly provided for in legislation. The case involved an injured seaman who sought damages under both negligence and unseaworthiness claims, but according to existing law at the time of his injury, he could only recover under one or other claim - not both simultaneously. Justice Frankfurter believed this limitation should be upheld as it reflected Congressional intent when drafting maritime laws; any changes should come from legislative action rather than judicial interpretation.