Barbara, USS = United State Ship ie. US Navy ship Liberty and Victory ships with the prefix SS were merchant marine ships not US Navy, even though they may have been troopships. SS denotes Steam Ship. Suggest http://www.usmm.org/ for more. Regards, Dave Barbara Phillips wrote: > Good Evening List, > I have a question about WWII Ships. Most US ships carry the USS before their names, however, the Liberty Ships were all simpley SS not USS. Is there anyone that knows why this was? They were also military ships. So I don't understand the difference. > Thank you, > Barbara Ann Phillips > bphil1@earthlink.net > > > >