Captain Chaplain Emil Kapaun leading Mass in October 1950 in Korea using the back of a Jeep as his makeshift altar.
Creator
Col. Raymond Skeehan
Source
Col. Raymond Skeehan. October 7, 1950. "Father Emil Kapaun celebrating Mass using the hood of a Jeep as his altar, Oct 7, 1950." Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Emil_Kapaun_Mass.jpg.