Below is a brief history of the K-Ration summarized from information found on the US Army Quartermasters Museum web site. Thank you QMC!

Field Ration K

The K ration was the Laboratory's answer to the demand for an individual, easy-to-carry ration that could be used in assault and combat operations. It was noted for compactness and superior packaging and was acknowledged as the ration that provided the greatest variety of nutritionally balanced components within the smallest space.

The first million K rations were ordered in May 1942 and were followed by increasing millions. In 1944, the peak year of production, more than 105 million rations were procured. Toward the end of the war, the usefulness of the K ration was coming to an end as a result of the emergence of a superior C ration. In postwar 1946, an Army Food Conference recommended that the K be discontinued and in 1948 the ration was declared obsolete by the Quartermaster Corps Technical Committee.42 It was then recommended that depot stocks be disposed of by utilization in the civilian feeding program overseas. Like other unpopular items, misuse was a contributing factor to the waning popularity of the K ration. Although designed to be used for a period of two or three days only, the ration occasionally subsisted troops for weeks on end. There were times when this application was unavoidable; there were also occasions when the K was employed because it was easiest to issue. Continued use reduced the acceptability and diminished the value of the ration.

For your viewing pleasure I have gatered some picsof the internal boxes. Ok that's enough of that. If you would like to read the rest of the story please see the QMC Museum Website.