Final answer:
Robert Kennedy, John F. Kennedy's brother and Attorney General, was assassinated on June 5, 1968, while running for president, impacting the civil rights movement and American politics.
Step-by-step explanation:
The brother of former president John F. Kennedy, Robert Kennedy, served as the Attorney General during his brother's administration and was later assassinated while running for president. Robert Kennedy was a vociferous supporter of civil rights and had a significant impact on the movement through his role in the administration and as a U.S. Senator representing New York. His assassination on June 5, 1968, by Sirhan Sirhan marked a tragic end to a campaign that many Americans believed could unify a nation deeply divided over civil rights and other social issues.