During the 20th century, Barnes commits numerous assassinations and terrorist acts throughout the world, such as the assassination of John F. Kennedy, as a means for Hydra to create a singular world government under their control.

Who assassinated JFK in Marvel?

Comic books

In the Ultimate Marvel universe, Kennedy's true assassin is Red Skull, the son of Captain America. Nick Fury muses that the assassination of Kennedy was the Skull's way of showing that he would no longer take orders from America.

Who has Bucky Barnes killed?

Bucky remained alone and on the run for two years even as Captain America and Falcon tried tracking him down. They finally caught up to him in Bucharest, after Barnes had been framed by Helmut Zemo for bombing the United Nations building in Vienna, killing King T'Chaka in the process.