On Earth-77105 events would diverge from Earth-616 during World War II at the moment when Captain America and Bucky would be attempting to stop Baron Zemo's drone plane. In this reality, Captain America would succeed in disarming the drone plane thus preventing Bucky's death and Captain America's plunge into the icy cold waters and subsequent suspended animation until the modern age.

As such, Captain America would remain active throughout World War II. Zemo's failure would lead to him being punished by Red Skull, blasted by an experimental suspended animation gun that would keep Zemo in suspended animation for the next 20-30 years. Captain America's addition to the war effort would be a great boon for the Allied Forces, and Cap and Bucky would fight along side the Howling Commandos until the war ended. Captain America would continue their career into the 1950's, batting Communist menaces to the Untied States while Nick Fury would die while on a tour of combat in Korea. As Bucky would grow older he would soon grow to resent Captain America's superior abilities and retire from costumed heroics, leaving Captain America to continue his crusade alone.

By the 1960's, Captain America would refuse an offer of membership with the newly formed Avengers, and later when President Lyndon B. Johnson would offer him the role as head of the new spy organization SHIELD to battle the terrorist organization known as Hydra, Cap would decline instead suggesting the position to his former partner Bucky, who now calling himself Buck. Buck would be a competent leader of SHIELD for many years.

When meeting together, Captain America and Buck would soon run into the Hulk and Rick Jones. During the fight, Cap's dulled reflexes would land him being injured, prompting Buck to jump into action and battle the Hulk, saving Rick from serious injury. Buck would take it upon himself to tell Steve that he was too old to be playing Captain America and the two would switch roles: Buck becoming Captain America, and Steve taking over his capacity as director of SHIELD. Rick would manage to blackmail the two men into letting him take on the role of Bucky or risk having their secret identities revealed to the world.

In his capacity of Captain America, Buck would fall in love and start a romance with SHIELD Agent 13, Sharon Carter. During this time Steve would lead SHIELD (with the new Cap's aid) on a strike on Hydra's headquarters. During the battle, Steve, Buck, and Sharon would be captured by the Supreme Hydra who would be revealed to be none other than Baron Zemo -- revived after his years of suspended animation. Wanting to get ultimate revenge against his hated foe Captain America, Zemo would be furious to find that the man under the mask was not the person he fought during World War II. During the fight Buck would take as fatal shot, and Baron Zemo would be incinerated in flowing magma when an explosion would breach the wall of his volcano base. SHIELD would succeed in ending the threat of Hydra, but at the expense of Buck's life.

At Buck's funeral, Steve would attempt to comfort Sharon who would lash out against him, furious that Buck would die on his last mission he was to go on before retiring and marrying her. Demoralized, Steve would pay a visit to a secret SHIELD base where a private museum commemorating Captain America is located. There Bucky would convince Steve that he could train him since he is getting older and SHIELD is not really Steve's true calling in life[1].

If Steve Rogers returned to his role of Captain America and/or if Rick Jones would succeed him are yet to be revealed.

Steve Rogers, Buck Barnes, Bucky, Howling Commandos (Nick Fury, Rebel Ralston), SHIELD (Sharon Carter,Dum Dum Dugan), Red Skull, Hydra (Baron Zemo/Supreme Hydra), Hulk

This reality the modern era of the Marvel universe took place in the 1960's. It is also noteworthy to identify that this issue was published prior to the retcon that would reveal that the Bucky of Earth-616 survived World War II and became Winter Soldier and (later) Captain America. It was a long standing belief in Marvel continuity that Bucky had died during World War II.