From Smash Comics #75 (February 1948), a Jack Cole story featuring Midnight, a character that was created to stand in for The Spirit. According to Will Eisner, "(Quality Comics Publisher Everett "Busy") Arnold got the idea that since the war was coming and I was going to be drafted ... he wanted to have somebody, in case I got killed, to replace the Spirit. Because I owned the Spirit and he knew if anything happened to me he couldn't continue it." I shiver to think what comics would look like today had Eisner met his doom in some muddy trench.
By the way, if you are a fan of Jack Cole, you owe it to yourself to check out this new blog.