U.S. Agent

U.S. Agent (real name John F. Walker), also seen as USAgent is a fictional character and comic book superhero appearing in books published by Marvel Comics, usually those starring the war hero Captain America and the Avengers. The character was created by Mark Gruenwald and the late Paul Neary and first appeared in Captain America #323 (November 1986) as Super-Patriot.

He was later redesigned as a new incarnation of Captain America after Rogers retired himself from the mantle and, just a few years later, as U.S. Agent when Rogers returned. Walker originally served as an antagonist towards Captain America, with him being considered a dark shadow of Rogers' patriotic and pacifist qualities. He would redeem himself and become the "U.S. Agent", protecting America's interest while becoming a member of numerous teams.