Robert Francis Kennedy was born on November 20, 1925, in Brookline, Massachusetts, the seventh child of businessman/politician Joseph P. Kennedy Sr. and philanthropist/socialite Rose Fitzgerald Kennedy. His older brothers were Joseph P. Kennedy Jr. and John F. "Jack" Kennedy, who was elected the 35th President of the United States in 1960. His younger brother was longtime United States Senator Edward M. "Ted" Kennedy. All four of his grandparents were children of Irish immigrants.

In Kennedy's younger years, his father dubbed him the "runt" of the family and wrote him off. Close family friend Lem Billings once remarked to Joe Sr. that he was "the most generous little boy", and Joe Sr. replied that he did not know where his son "got that". Billings commented that the only similarity between Robert and Joe Sr. was their eye color. As Kennedy grew, his father worried that he was soft on others, conflicting with his ideology. In response, Kennedy developed a tough persona that masked his gentle personality, attempting to appease his father. Biographer Judie Mills wrote that Joe Sr.'s lack of interest in Robert was evident by the length of time it took for him to decide to transfer him to Milton Academy. Both Joe Jr. and John attended the exclusive Protestant prep school Choate from their freshman year, while Robert was already a junior by the time he was enrolled at Milton. Despite his father's disdain, Kennedy continued to seek his approval, requesting that Joe Sr. write him a letter about his opinions on different political events and World War II. As a child, Kennedy also strove to meet his mother's expectations to become the most dutiful, religious, affectionate, and obedient of the Kennedy children, but the father and son grew distant. Rose found his gentle personality endearing, though this was noted as having made him "invisible to his father". She influenced him heavily and like her, he became a devout Catholic and throughout his lifetime he practiced his religion more seriously than the other boys in the family. He impressed his parents as a child by taking on a newspaper route, seeking their approval and wishing to distinguish himself. However, he had the family chauffeur driving him in a Rolls-Royce so that he could make his deliveries. His mother discovered this and the deliveries ceased. Joe Sr. was satisfied with Kennedy as an adult, believing him to have become "hard as nails", more like him than any of the other children, while his mother believed he exemplified all she had wanted in a child. Mills wrote, "His parents' conflicting views would be echoed in the opinions of millions of people throughout Bobby's life. Robert Kennedy was a ruthless opportunist who would stop at nothing to attain his ambitions. Robert Kennedy was America's most compassionate public figure, the only person who could save a divided country." In November 1951, Kennedy moved with his wife and daughter to a townhouse in Georgetown in Washington, D.C., and started work as a lawyer in the Internal Security Section of the Criminal Division of the U.S. Department of Justice; the section was charged with investigating suspected Soviet agents. In February 1952, he was transferred to the Eastern District of New York in Brooklyn to prosecute fraud cases. On June 6, 1952, Kennedy resigned to manage his brother John's successful 1952 U.S. Senate campaign in Massachusetts. JFK's victory was of great importance to the Kennedy family, elevating him to national prominence, and turning him into a serious potential presidential candidate. But his brother's victory was equally important to Robert, who felt he had succeeded in eliminating his father's negative perceptions of him. In December 1952, at the behest of his father, Kennedy was appointed by family friend Republican Senator Joseph McCarthy as assistant counsel of the U.S. Senate Permanent Subcommittee on Investigations, However, Kennedy disapproved of the senator's aggressive methods of garnering intelligence on suspected communists. This was a highly visible job for him. He resigned in July 1953, but "retained a fondness for McCarthy". The period of July 1953 to January 1954 saw him at "a professional and personal nadir", feeling that he was adrift while trying to prove himself to the rest of the Kennedy family. After a period as an assistant to his father on the Hoover Commission, Kennedy rejoined the Senate committee staff as chief counsel for the Democratic minority in February 1954. That month, McCarthy's chief counsel Roy Cohn subpoenaed Annie Lee Moss, accusing her of membership in the Communist Party. Kennedy revealed that Cohn had called the wrong Annie Lee Moss and he requested the file on Moss from the FBI. FBI director J. Edgar Hoover had been forewarned by Cohn and denied him access, referring to RFK as "an arrogant whipper-snapper". When the Democrats gained the majority in the Senate in January 1955, Kennedy became chief counsel and was a background figure in the televised Army-McCarthy Hearings of 1954 into McCarthy's conduct. The Annie Lee Moss incident turned Cohn into an enemy, which led to Kennedy assisting Democratic senators in ridiculing Cohn during the hearings. The animosity grew to the point where Cohn had to be restrained after asking RFK if he wanted to fight him. For his work on the McCarthy committee, Kennedy was included in a list of Ten Outstanding Young Men of 1954, created by the U.S. Junior Chamber of Commerce. His father had arranged the nomination, his first national award. In 1955, Kennedy was admitted to practice before the United States Supreme Court. In 1960, Kennedy published the successful book, which he had drafted over the summer of the previous year, The Enemy Within, describing the corrupt practices within the Teamsters and other unions that he had helped investigate. Biographer Evan Thomas wrote that the book was a bestseller and could have launched a political career on its own, but "family duty called", and Kennedy went to work on the presidential campaign of his brother, John. In contrast to his role in his brother's previous campaign eight years prior, Kennedy gave stump speeches throughout the primary season, gaining confidence as time went on. His strategy "to win at any cost" led him to call on Franklin D. Roosevelt Jr. to attack Hubert Humphrey as a draft dodger; Roosevelt eventually did make the statement that Humphrey avoided service. Concerned that John Kennedy was going to receive the Democratic Party's nomination, some supporters of Lyndon Johnson, who was also running for the nomination, revealed to the press that JFK had Addison's disease, saying that he required life-sustaining cortisone treatments. Though in fact a diagnosis had been made, Kennedy tried to protect his brother by denying the allegation, saying that JFK had never had "an ailment described classically as Addison's disease". After securing the nomination, John Kennedy nonetheless decided to offer Lyndon Johnson the vice presidency. This did not sit well with some Kennedy supporters, and Robert tried unsuccessfully to convince Johnson to turn down the offer, leading him to view Robert with contempt afterward. RFK had already disliked Johnson prior to the presidential campaign, seeing him as a threat to his brother's ambitions. RFK wanted his brother to choose labor leader Walter Reuther. Despite Kennedy's attempts, Johnson became his brother's running mate. Kennedy worked toward downplaying his brother's Catholic faith during the primary but took a more aggressive and supportive stance during the general election. These concerns were mostly calmed after JFK delivered a speech in September in Houston where he said that he was in favor of the separation of church and state. The following month, Kennedy was involved in securing the release of civil rights leader Martin Luther King Jr. from a jail in Atlanta. Kennedy spoke with Georgia governor Ernest Vandiver and later, Judge Oscar Mitchell, after the judge had sentenced King for violating his probation when he protested at a whites-only snack bar. CANNOTANSWER

Using a quote from the above article, answer the following question: When did he join the campaign?

In 1960,