Collects Captain America (1968) #127-156.
*Cap's up against the usual army of orders in AIM, Hydra and the schemes of the Skull -- but could the most familiar enemy face be...Bucky's?! The Falcon becomes Cap's full-time crimefighting partner in the wake of this shocker! Gangsters and gorillas! A mysterious Stranger! Nazis, robots and Nazi robots! Featuring the friends and foes of Spider-Man, and the web-slinger himself! Guest-starring Daredevil and the Avengers! Plus: the secret of the 1950s Captain America and Bucky, foreshadowing the first appearance of the man called Nomad! *Source: marvel.com