Born as Calogero Minacori (or Minacore) to Sicilian parents in Tunis, French Tunisia, Marcello was brought to the United States in 1911 and his family settled in a decaying plantation house near Metairie in Jefferson Parish in suburban New Orleans. Young Marcello turned to petty crime in the French Quarter. He was later imprisoned for masterminding a crew of teenage gangsters who carried out armed robberies in the small towns surrounding New Orleans. At the time, local newspapers compared him to the character of Fagin from Charles Dickens' novel Oliver Twist. This conviction was later overturned. However, the following year he was convicted of assault and robbery and was sentenced to the Louisiana State Penitentiary in West Feliciana Parish for nine years. He was released after five years.
In 1938, Marcello was arrested and charged with the sale of more than 10 kg (23 pounds) of marijuana. Despite receiving another lengthy prison sentence and a $76,830 fine, Marcello served less than ten months. On his release from prison, Marcello became associated with Frank Costello, the leader of the Genovese crime family, in New York City. At the time, Costello was involved in transporting illegal slot machines from New York City to New Orleans. Marcello provided the muscle and arranged for the machines to be placed in local businesses.
By the end of 1947, Marcello had taken control of Louisiana's illegal gambling network. He had also joined forces with New York Mob associate Meyer Lansky in order to skim money from some of the most important casinos in the New Orleans area. According to former members of the Chicago Outfit, Marcello was also assigned a cut of the money skimmed from Las Vegas casinos, in exchange for providing "muscle" in Florida real estate deals. By this time, Marcello had been selected as "The Godfather" of the New Orleans Mafia, by the family's capos and the National Crime Syndicate after the deportation of Sylvestro "Silver Dollar Sam" Carolla to Sicily. He held this position for the next thirty years. In a 1975 extortion trial, two witness described Marcello as "The Godfather" of the New Orleans crime syndicate.
Marcello appeared before the U.S. Senate's Kefauver Committee on organized crime on January 25, 1951. He pleaded the Fifth Amendment 152 times. The Committee called Marcello "one of the worst criminals in the country."
Marcello continued the family's long-standing tradition of fierce independence from interference by mafiosi in other areas. He enacted a policy that forbade mafiosi from other families from visiting Louisiana without permission.
On March 24, 1959, Marcello appeared before the United States Senate's McClellan Committee investigating organized crime. Serving as Chief Counsel to the committee was Robert F. Kennedy; his brother, Senator John F. Kennedy, was a member of the committee. In response to committee questioning, Marcello invoked the Fifth Amendment and refused to answer any questions relating to his background, activities, and associates.
In 1960, Marcello donated $500,000 through Teamsters Union president Jimmy Hoffa, to the Republican campaign of Richard M. Nixon, who unsuccessfully opposed the Democrat John F. Kennedy.
On April 4, 1961, Marcello was arrested while making what he thought was a routine visit to the immigration authorities in New Orleans, and forcibly transported to Guatemala, but two months later he was back in New Orleans. Thereafter he successfully fought further efforts by the government to deport him. His immigration lawyer was David Carliner.
In November 1963, Marcello was tried for "conspiracy to defraud the United States government by obtaining a false Guatemalan birth certificate" and "conspiracy to obstruct the United States government in the exercise of its right to deport Carlos Marcello." He was acquitted later that month on both charges. However, in October 1964, Marcello was charged with "conspiring to obstruct justice by fixing a juror [Rudolph Heitler] and seeking the murder of a government witness [Carl Noll]." Marcello's attorney admitted Heitler had been bribed but said that there was no evidence to connect the bribe with Marcello. Noll refused to testify against Marcello in the case. Marcello was acquitted of both charges.
In September 1966, 13 members of the New York, Louisiana and Florida crime families were arrested for "consorting with known criminals" at the La Stella Restaurant in Queens, New York. However, the charges were later dropped. Returning to New Orleans a few days later, Marcello was arrested for assaulting an FBI agent. His first trial resulted in a hung jury, but he was retried and convicted. He was sentenced to two years but served less than six months.
In 1981, Marcello, Aubrey W. Young (a former aide to Governor John J. McKeithen), Charles E. Roemer, II (former commissioner of administration to Governor Edwin Edwards), and two other men were indicted in the U.S. District Court for the Eastern District of Louisiana in New Orleans with conspiracy, racketeering, and mail and wire fraud in a scheme to bribe state officials to give the five men multimillion-dollar insurance contracts. The charges were the result of a Federal Bureau of Investigation probe known as BriLab. U.S. District Judge Morey Sear allowed the admission of secretly-recorded conversations that he said demonstrated corruption at the highest levels of state government. Marcello and Roemer were convicted, but Young and the two others were acquitted.
In its investigation of the assassination of John F. Kennedy, the House Select Committee on Assassinations said that it recognized Jack Ruby's murder of Lee Harvey Oswald as a primary reason to suspect organized crime as possibly having involvement in the assassination. In its investigation, the HSCA noted the presence of "credible associations relating both Lee Harvey Oswald and Jack Ruby to figures having a relationship, albeit tenuous, with Marcello's crime family or organization." Their report stated: "The committee found that Marcello had the motive, means and opportunity to have President John F. Kennedy assassinated, though it was unable to establish direct evidence of Marcello's complicity."
Author John H. Davis in his 1989 book Mafia Kingfish: Carlos Marcello and the Assassination of John F. Kennedy implicates the mafia and Marcello in the assassination of Kennedy. According to Davis, Oswald and Ruby had "strong ties" to Marcello, and that an Oswald impostor visited the Russian embassies in Cuba and Mexico.
Attorney Frank Ragano said in his 1994 autobiography Mob Lawyer that he relayed a message from Hoffa to Marcello and Santo Trafficante, the Mafia boss of Florida, asking the two Mafia bosses if they would kill Kennedy.
In his 2013 book The Hidden History of the JFK Assassination, Lamar Waldron states that Marcello masterminded the assassination of Kennedy. Waldron said Marcello admitted his involvement to two other inmates during a fit of rage in the prison yard at the Federal Correctional Institution in Texarkana, Texas. According to Waldron, Marcello arranged for two hit men to carry out the assassination after entering the United States from Canada and Europe.
Early in 1989, Marcello suffered a series of strokes. In July, in a surprise move, the 5th U.S. Circuit Court of Appeals threw out his BriLab conviction. One judge denied this reversal, but his decision in turn was overruled. In October, after having served six years and six months of his sentence, Marcello was released, and the old don was finally returned into his family’s care. "I’m retired," he told reporters. "I’m happy. Everybody’s been nice to me." He returned to his white marble, two-story mansion overlooking a golf course in Metairie.
Here, he lived out the last years of his life, cared for by a group of nurses and watched over by his wife and family. Carlos Marcello died on March 2, 1993.
The New Orleans crime family frequently met at a well-known exclusive Italian restaurant in the New Orleans suburb of Avondale, known as Mosca's. It has been said that Mosca's was the epicenter for Carlos Marcello and his many associates. It is still in operation today after renovations following Hurricane Katrina by the Mosca family.
In Bryce Zabel's 2014 novel Surrounded by Enemies: A Breakpoint Novel, in an alternate universe where President Kennedy survived the assassination, but agent Clint Hill and Texas Governor John Connally were killed, President Kennedy talked to his brother Attorney General Robert F. Kennedy, discussing suspects, including Marcello. Codenamed "New Orleans", Marcello was said to have motive and resources to carry out the attack.