Jack Monroe was the "Bucky" of the Captain America who acted during the Fifties, and got a similar treatment than his partner. However, since they used the Super-Soldier serum without the stabilizing addition of the Vita-Rays, the new Captain America and Bucky gradually went insane after several missions, and began attacking anyone they thought might be a communist enemy. They were captured by the FBI and put into suspended animation.
Monroe and the "50's Captain America" got free of their suspended animation in the present day, and faced the original Captain America and Falcon, as they mistook the original Cap for an imposter. Steve and Falcon defeated the fake Captain America and Bucky and put them back in suspended animation, where they were found by Doctor Faustus who used them for criminal goals. Faustus' eventual defeat would get Jack Monroe in the hands of S.H.I.E.L.D. who gave him a psychiatric treatment to get back his sanity, after which they offered him the costume and name of Nomad, which had already been used once by Steve Rogers himself.
Nomad helps Cap several times, but the Red Skull brainwashes him into secretly dosing Cap's food with a chemical that reverses the Super-Soldier serum, so he has the same accelerated aging disease as the Skull. The Skull also captures Nomad, among others, to lure Captain America into a trap. Eventually, the Skull dies and Cap recovers.
When Steve was stripped of his Captain America costume, shield and identity and became the Captain, Nomad was one of his allies, alongside D-Man, Falcon and his girlfriend Vagabond. D-Man trained Vagabond in hand-to-hand combat, which Nomad misinterpreted as D-Man hitting on her. When the Captain and his allies faced the Serpent Society, Slither attacks D-Man, and while Nomad hesitates from helping D-Man for what happened before, he finally knocks Slither out. Nomad interrogates Slither and finds out Viper sent three Serpent Society members to poison the water supply of Washington. The "poison" turns out to be a mutagenic agent based on Slither's genes, which turns the citizens into snake people. When pursuing Cobra, Nomad faced several mutated citizens, who overpowered him when a flare from Cobra blinded him. Nomad survived and was imprisoned by the CSA
Vagabond went with a Sidewinder to free D-Man, Diamondback and Nomad, but when D-Man decided that escaping would be wrong, Vagabond staid with him, which caused Nomad to break up with Vagabond. Monroe went to a tavern and got drunk, then called Rogers and told him about what happened to D-Man and Vagabond. When Steve decided to turn himself in exchange of their friends, Monroe considered it a stupid idea and left.