John Steele is an agent with American Intelligence.
Exactly which department he is connected with is never revealed. He is called in on his first set of adventures by the military leaders of NATO but he comes dressed in civilian attire and when he is introduced by the man giving the briefing, he is only identified by name and by the title "Freedom Agent".
Very little is revealed in any of the missions we can see him perform. From his appearance it would be safe to assume he is in his mid 30's. This is further evidenced by his calm and mature manner (not brash or anxious at all) and when it is pointed out that should he be captured, he was decidedly on his own, Steele did not look at all surprised or put out. His age is not likely anymore, though, because in his first recorded adventure he is shown to have a terrific physique complete with washboard abs.
Steele is an expert with languages. In one mission he must impersonate a Russian guard to infiltrate a secret facility and he does so without anyone becoming suspicious. In another he is sneaking into Chinese controlled Tibet and he is able to converse with the people smuggling him in as well as understand what Chinese guards are saying. Finally, in the last adventure we can follow, he must take the place of a Latin American dictator, clearly showing an intimate knowledge of Spanish.
Steele is definitely a man of action and self-reliance but he is also quite intelligent and resourceful. When faced with apparently invisible opponents, he picks up readily the science thrown at him. Similarly when stuck behind the Bamboo Curtain with a broken radio and a need to signal his bosses, he is able to tinker enough with it to get is working again, albeit for just a short period.
Where Steele comes from and where he heads when he is off duty is never revealed. What is shown is how much excitement routinely heads his way.