Captain America #110 (1969)

While on a walk in his civilian identity, Steve Rogers pauses to light a pipe and looks at a poster advertising a charity appearance for Captain America. His thoughts about his troubled life are cut as the Hulk smashes through the wall in another one of his rampages through New York City. Steve changes into Captain America and goes after the Green Goliath to try and stop him from hurting anyone. When the Hulk is knocked down by a barrage of military gun fire, Captain America tries to approach the brute, but is distracted by the passionate cries of Rick Jones. Rick tries to tell Cap that the Hulk isn't a threat, and when the Hulk tries to escape with the boy, he only succeeds in injuring him when trying to fight off Cap and the military. The Hulk then bounds away leaving the injured Jones with Captain America. Cap takes his one-time sidekick back to Avengers Mansion to recover, and as Rick sleeps Cap once more broods about how easily people in his life can be injured. His thoughts are distracted by footsteps behind him and he turns to find that Rick is up and about and wearing Bucky's uniform. Rick asks to be Cap's sidekick once more and to be the new Bucky. Cap at first cannot stand to have someone else wear the uniform much less the risk of losing their lives as his sidekick. Rick feels rejected which causes Captain America to change his mind and when the alarm in Avengers Mansion goes off, he takes him out on their first patrol together as the new Captain America and Bucky team. Descending into the sewers under Avengers Mansion they find that the Hydra army is down there with their new leader, Madame Hydra. As the battle rages, Captain America continues to fear for Rick's safety, at one point pulling some fast moves to prevent him from coming to harm. Deciding that this battle is too much for the novice Rick, Captain America orders him to retreat. Cap is then attacked by a Hydra soldier wearing a power vest and seemingly defeated. Unknown to Madame Hydra and the others, Captain America defeated the soldier in the power vest and put on his uniform in order to infiltrate Hydra and gain access to Madame Hydra. Seeing what appears to be Cap's demise, Rick runs back into the fray, spoiling Cap's plan when the hero has to blow his cover in order to save Rick. Madame Hydra manages to capture Rick and pushes him over a ledge, forcing Cap to go to his rescue while she escapes. In the aftermath of the battle, Captain America tells Bucky that in the future he will have to learn to follow his orders without question, but tells him that he fought like a man in battle. Rick thinks to himself that while he may not currently be as good as the original Bucky, he won't stop trying to eventually measure up.