Top secret law-enforcement division appearing in Marvel Comics
first appeared in Strange Tales #135
During the heart of the cold war and in the heyday of such characters as James Bond and the Man from U.N.C.L.E., Marvel Comics decided to get into the spy game with their own spy group. The group was organized by the the United Nations and overseen by a shadowy group of high level politicians and industrialists, of whom Tony Stark, the owner of Stark Industries and alter-ego of the invincible Iron Man, was a part. The group was given the rather lengthy name of Supreme Headquarters International Espionage Law-enforcement Division so that they could have the really cool acronym of S.H.I.E.L.D.. Although their missions were top-secret, a Public Director was named to be the public face of S.H.I.E.L.D. The first Public Director was a man named Rick Stoner, though the paint wasn't even dry on his door before he was assassinated. The assassination was carried out by a group who would be S.H.I.E.L.D.'s archnemesis through the years, HYDRA.
The next man named for the post of Public Director was a former Army officer and CIA agent, Nick Fury. Fury was now a colonel and his first experience with S.H.I.E.L.D. was to save the oversight committee from a bomb aboard a S.H.I.E.L.D. helicarrier. Fury was given the post of Public Director and spent the next twenty years fighting such threats as HYDRA and AIM. S.H.I.E.L.D. turned up in the adventures of Fantastic Four and the Avengers. S.H.I.E.L.D. was also responsible for helping to fight the menace of Godzilla when that standard of Japanese cinema was briefly part of the Marvel Universe.
By the mid-80's, the cast of S.H.I.E.L.D. characters had become huge: Clay Quartermaine, Jimmy Woo, Jasper Stillwell, and the Countess Valentina Allegro DeFontaine as well as old Sgt. Fury and Howling Commandos regulars Gabe Jones and Dum Dum Dugan. A storyline about a group of LMD (life model decoys) calling themselves Deltites taking over S.H.I.E.L.D. from within and trying to get a sample of the Infinity Formula that keeps Nick Fury alive and active over all these years had the net result of killing many of the extaneous characters and causing the United Nations to disband S.H.I.E.L.D. for a time.
With the rise in terrorism and the return to the world scene of HYDRA, the UN activated a new group agency with the same acronym. S.H.I.E.L.D. (Strategic Hazard Intelligence Espionage and Logistics Directorate) was once again in active service with Nick Fury at the helm. Now a smaller and tighter group, S.H.I.E.L.D. still fights against the forces of evil in the world.
S.H.I.E.L.D. stories have produced some of the most memorable of all gadgetry in the Marvel Universe. The L.M.D. or life model decoy is a robot creation that can be programmed to look an act like the person it is duplicating to trick opponents and stand in for absent agents (think Superboy's robot doubles). Other gadgetry includes the S.H.I.E.L.D. helicarrier which was the equivalent of a battleship that flies via multple propellers and the flying car, which has wheels that fold up revealing engines that cause the car to fly.