Brief History
Gideon is the older brother of Sam Wilson, the Falcon. He became part of the Gamma Corps after it was brought into existence after the events of World War Hulk. Gideon signed on with Gamma Corps because he feels the Hulk is responsible for the death of his son, Jim.
Creation
Mister Gideon was created by Frank Tieri and Carlos Ferreira and first appeared in World War Hulk: Gamma Corps #1.