© Getty Images

Early life -

James Riddle Hoffa was born on February 14, 1913. The son of an Indiana coal miner who died when he was seven, the family moved to Detroit in 1924, where Hoffa was raised and lived for the rest of his life.

© Getty Images

Marriage and family -

In September 1937, Hoffa married Josephine Poszywak, a laundry worker of Polish heritage. The couple had two children: a daughter, Barbara Ann, and a son, James P. Hoffa.

© Getty Images

Union activism -

It was in the 1930s that Jimmy Hoffa began his union-organization activities through his job with a local grocery chain. After successfully orchestrating his first labor strike, helping co-workers land a better contract, he was invited to become an organizer with Local 299 of the Teamsters in Detroit.

© Getty Images

International Brotherhood of Teamsters -

Founded in 1903, the International Brotherhood of Teamsters (IBT) is America's largest, most diverse union. Historically, the term "teamsters" referred to commercial road transportation workers. By the early 1950s, Teamsters' membership topped over a million.

© Getty Images

Trucking and crime -

Trucking unions in that era were heavily influenced by, and in many cases controlled by, elements of organized crime.

© Getty Images

Vice presidency of IBT -

In 1952, Hoffa's grip on union labor was considerably strengthened after he was elected as international vice president of the Teamsters. Meanwhile, organized crime's influence on the IBT increased as the union grew.

© Getty Images

Gunning for the top job -

Five years later, Hoffa stood as candidate for President of the Teamsters Union after incumbent Dave Beck declined to seek reelection. Hoffa's outwardly genial character hid a fearless and intimidating persona.

© Getty Images

On the campaign trail -

Hoffa's run for the Teamsters' top job saw him campaigning in Miami, Florida. He's seen here signing an autograph on a placard for female admirers.

© Getty Images

Hoffa and the Kennedy brothers -

Hoffa was elected president of the IBT in 1957, a position he would hold until 1971. For the rest of his career, his name would be associated with alleged ties to organized crime. But even before becoming president, Hoffa was already facing major criminal investigations in 1957 as a result of the United States Senate Select Committee on Improper Activities in Labor and Management, also known as the McClellan Committee. Headed by Senator John L. McClellan, the select committee's assistant lead counsel was Robert F. Kennedy.

© Getty Images

Facing union wrath -

Robert F. Kennedy was joined on the committee by his brother, Senator John F. Kennedy, sitting in his capacity as Labor chairman. Both would take the brunt of organized labor's outrage.

© Getty Images

The McClellan hearings -

The McClellan Committee had essentially been established at the behest of big businesses and anti-union politicians.

© Getty Images

Hoffa under the spotlight -

Its function was to investigate labor racketeering. In March 1957 during the hearings, Hoffa was actually arrested for allegedly trying to bribe an aide to the select committee.

© Getty Images

Caught in the act -

That man was John Cye Cheasty. Cheasty was recruited by Hoffa to spy on the Senate committee. He met Hoffa in Detroit, was given a US$2,000 a month retainer, and then arranged to join the staff of the Senate committee, whose chief counsel was, of course, Robert F. Kennedy. However, Cheasty agreed to pass fake documents to a none-the-wiser Hoffa while actually working with Kennedy, who was building a bribery case against the Teamsters leader.

© Getty Images

Hoffa denies any wrongdoing -

Hoffa vigorously denied recruiting Cheasty, but his arrest triggered additional investigations and more arrests and indictments over the following weeks.

© Getty Images

Fraternizing with mobsters -

The Teamsters president rejected the accusation that he had fraternized with mobster Johnny Dio, known for his role in creating fake labor union locals to help Hoffa become the Teamsters' boss.

© Getty Images

Acquitted -

Despite impressive evidence against him, Hoffa was eventually acquitted of all charges. Apparently vindicated, Hoffa ultimately secured the vote as President of the IBT.

© Getty Images

Denouncing his detractors -

Hoffa then went on the offensive. He appeared on NBC's 'Today' program and claimed that Robert F. Kennedy "deliberately distorted the truth... in a mad desire to advertise his brother's candidacy for president." John F. Kennedy was inaugurated as the nation's 35th president on January 20, 1961.

© Getty Images

Hoffa the hero -

Jimmy Hoffa was regarded by IBT members as a hero. A crowd of 10,000 turned up to hear him speak at Madison Square Garden in New York as he campaigned against the Labor Reform Law, passed in 1959 by Congress.

© Getty Images

"Get Hoffa" -

In 1961, Robert F. Kennedy had been appointed by the president as attorney general. He renewed his efforts in attacking organized crime and carried on with a so-called "Get Hoffa" squad of prosecutors and investigators. New allegations leveled against Hoffa included a charge that real estate allegedly purchased by him for members of organized crime had been acquired using union funds.

© Getty Images

Real estate scams -

This is an aerial view of an uncompleted housing project that Hoffa and two of his associates were accused of misusing union funds in promoting and developing in Brevard County, Florida.

© Getty Images

More conspiracy charges -

In 1962, Hoffa faced trial in Nashville, his fourth trial since the mid-1950s. On this occasion, he was charged along with another Teamster official of accepting more than US$1 million in illegal payments from a Detroit trucking business. But he was also later charged with the attempted bribery of a grand juror.

© Getty Images

Arrested and convicted -

He was convicted in March 1964 of conspiracy and sentenced to eight years in prison. While on bail during his appeal, Hoffa was again arrested and subsequently convicted in a second trial held in Chicago, on July 26, 1964. Found guilty of conspiracy and three counts of mail and wire fraud for improper use of the Teamsters' pension fund, Hoffa was sentenced to a total of 13 years in prison.

© Getty Images

Jailed -

The disgraced union boss was sent to the Lewisburg Federal Penitentiary in Pennsylvania to serve his time. Hoffa refused to resign as president of the Teamsters while in prison, and kept his position until 1971.

© Getty Images

Nixon commutes sentence -

In 1971 after serving five years of his sentence, Hoffa was released from prison when US President Richard Nixon commuted it to time served. The IBT then endorsed Nixon in his presidential reelection bid in 1972.

© Getty Images

Hoffa's second bid for the IBT presidency -

As part of the deal in commuting his sentence, Hoffa was not allowed to engage in any kind of union activity until 1980. However, by 1973 Hoffa was planning to seize the presidency of the Teamsters again.

© Getty Images

Disappearance -

Hoffa's wishes to regain the leadership of the union were met with hostile opposition from several members of the Mafia, including Anthony Provenzano and Anthony Giacalone. On July 30, 1975, Hoffa agreed to meet the two mobsters at the Machus Red Fox restaurant in Bloomfield Township, a Detroit suburb. However, neither turned up. Hoffa left the location and was never seen again.

© Getty Images

Never seen again -

During the FBI investigation into Hoffa's disappearance, Giacalone and Provenzano denied having scheduled a meeting with Hoffa. Later, acting on a tip-off, a 55-gallon drum of the type reportedly used to transport the body of the former Teamster boss to New Jersey was found in a landfill area in Jersey City, where the FBI had obtained a search warrant to dig for a body.

© Getty Images

Burial site? -

Speculation as to Hoffa's fate has baffled the FBI for 50 years. It's generally assumed that his body was indeed disposed of in an area near the industrial site in Jersey City where the drum was found in 1975.

© Getty Images

New leads -

In 2006, the FBI tore down a barn in Milford, Michigan, after receiving a tip that Hoffa was buried on farmland.

© Getty Images

More clues -

Another anonymous phone call in 2012 had police employ ground penetrating radar in a residential neighborhood of Roseville, also in Michigan, in the hope of revealing a burial site. 

© Getty Images

One last search -

And the following year, FBI agents searched a field in Oakland Township outside Detroit for the alleged remains of the former Teamsters' union president.

© Getty Images

"Presumed dead" -

Hoffa is believed to have been murdered by the Mafia. His remains have never been found. He was legally declared "presumed dead" in 1982.

Sources: (Biography) (Detroit Free Press) (History.com) (FBI) 

See also: Who are the most infamous mobsters and gangsters?

© Getty Images