I saw these at the Post Office yesterday and had to scoop up a few sheets (yes, I am one of those dinosaurs who still writes letters and mails checks). The U.S. Postal Service has just issued a new set of "forever" stamps, meaning they never expire, and this one is dedicated to the U.S. Merchant Marine.
The four stamps depict a clipper ship, auxiliary steamship, WW II Liberty ship (my favorite), and modern container ship. One one side of the sheet is a brief history of the modern U.S. Merchant Marine, in peace and war. About time these guys (and a few ladies) got their due, for all the sacrifices they have made. I've scanned a copy of the artwork, with the postage notation defaced to keep me out of trouble with Uncle Sam. Personally, I think these are great!: