Final answer:
Robert F. Kennedy was assassinated by Sirhan Sirhan on June 5, 1968, at the Ambassador Hotel in Los Angeles, after a critical primary win in his presidential campaign.
Step-by-step explanation:
Robert F. Kennedy, a key political figure and advocate for civil rights, was assassinated on June 5, 1968, by Sirhan Sirhan, not Lee Harvey Oswald, James Earl Ray, or Jack Ruby. This tragic event occurred at the Ambassador Hotel in Los Angeles after Kennedy had won the California Democratic primary in his bid for the presidential nomination. His death was a significant blow to the civil rights movement and the hopes of many for future progress in America.