1956:

The US Coast Guard issued new regulations for security screening of merchant seamen.  Changes in the screening program were made for the purpose of conforming with a recent US Court of Appeals ruling (Parker V. Lester) which, held that procedures used by the Coast Guard did not meet the minimum requirements of due process of law.  The legal background for the Coast Guard security program stems from the Magnuson Act, which authorized the President to issue rules safeguarding vessels and waterfront facilities when he found security endangered by a subversive activity.  The President made such a finding in 1950 by Executive Order Number 10173 and directed the Coast Guard to set up and conduct the program.