I understand that the C-rations and K-rations were surplus US Army lefftovers from WWII, but when you are hungry, they are very good!
In 1969, my company, A-1/61 IN, was issued C-rations dated 1944. They were edible. The cigarettes, not so good. :-)

My brigade (1st Bde, 5th ID) was part of the 3rd Marine Division -- the second Army-Marine division in American history to see combat (the other being the 2nd Infantry Division in WWI.)