I am trying to find out more about a merchant navy sea captain who held a US Master Mariner's license between about 1874 (year he was naturalized citizen), and 1896 (when his license expired). I have searched the list archives, and the FAQ but cannot find anything relevant (so excuse me if I have missed it). I have searched the US National Archives web site, but cannot find anything about Master Mariner licenses. I understand that licensing was/is the responsibility of the US National Coast Guard Agency, but can find nothing on their web site about their archives either. Is there an equivalent of Lloyd's Captain's Registers for the USA? Any help would be appreciated. Many thanks,  Steve