A weird relic rested on the bookcase in my family's last home in New Orleans: a wooden pipe that had belonged to Jim Garrison, the Orleans Parish district attorney who tried and failed to convict a local businessman named Clay Shaw for the assassination of President John F. Kennedy. The pipe still smelled of the tobacco its owner had packed and lit before setting it down at a cocktail party. Garrison—that's him on the right—had left the party and forgotten his pipe. And because he was still a hero to some, and especially to my mom, she took Garrison's pipe home as a souvenir.

If you know about Jim Garrison, you probably learned about him from the 1992 movie JFK, in which Kevin Costner portrayed him as an impossibly brave hero fighting the vast coiled insanity of corrupt government and constant war. Garrison/Costner also delivered the greatest closing argument in the history of film, a jackhammer attack in a folksy New Orleans drawl that permanently infected a generation with the conspiracy virus.

In New Orleans, the dead are never far from daily conversation. Kennedy had been killed years before I was born, but the ghosts of the murdered president and his alleged lone assassin were a constant presence.

By the time my mom nabbed his pipe, Jim Garrison had become a laughingstock of the American establishment, the same establishment of journalists and political operatives who let Vietnam happen without a complaint, who smeared and destroyed anyone who stepped out of line, whether it was Lenny Bruce or Montgomery Clift or an unhinged crusader like Garrison who was trying to solve the assassination of a president. By 1973, he washed out as the local district attorney, having lost his latest re-election campaign to another handsome smooth talker, Harry Connick Sr.

Despite Garrison's failure, despite himself and despite an unprecedented national attack on his character by every goon employed by the U.S. military-industrial-media complex, people like my mother loved Jim Garrison because he tried to prove what everybody already believed. Even the racists and anti-papists who hated Kennedy believed he'd been taken out by a shadow government, which is why you often heard this phrase in the South in the days after November 22, 1963: They finally got the sonofabitch.

On the 50th anniversary of JFK's murder in Dallas, an overwhelming majority of Americans still believes Kennedy's assassination was the result of a wider conspiracy—75 percent are skeptics of the official story, which makes skepticism of the official story far more popular than the Democrats or the Republicans or any politician alive. The U.S. government has come to two entirely different official conclusions, with the 1964 Warren Commission finding that Lee Harvey Oswald acted alone, and the 1978 U.S. House Select Committee on Assassinations settling on a vague conspiracy with Oswald as the gunman. The most relevant papers continue to be sealed, because the CIA will not release 1,171 remaining documents related to the assassination.

Lee Harvey Oswald briefly met my mother in August of 1963, when she worked as a secretary at New Orleans' International Trade Mart on the corner of Camp and Common streets. A local boy and ex-Marine, Oswald was handing out pro-Castro fliers to office workers returning from lunch. My mom took one, glanced at the text praising Communist Cuba, and tossed the leaflet in a trash can in the Trade Mart lobby.

Outside, some anti-Castro Cubans suddenly appeared and started a scene. Cops broke up the scuffle and arrested Oswald for disturbing the peace, a minor incident reported by the local news. That the anti-Castro Cubans knew the supposedly pro-Castro Oswald was just one of those things. That Oswald's leaflets were stamped with the anti-Castro group's New Orleans address was another one of those things.

When Lee Harvey Oswald's face took over every American television screen a few months later, after Dallas police claimed the president's killer had been found hiding in a movie theater matinee, it was deeply shocking to my mother and everyone else in New Orleans who had heard about this oddball pacing the sidewalks downtown with his "Fair Play For Cuba" fliers.

It had a peculiar effect on Jim Garrison, too. He came to see New Orleans' central business district as the nexus of a successful plot to murder the president. Clay Shaw had founded the Trade Mart, and Oswald was hanging around with all manner of unsavory anti-Castro and right-wing crooks with weird ties to U.S. intelligence and the Mafia, conveniently right there in the lazy city where Garrison was a press-hungry district attorney.

After Shaw was acquitted, Garrison was slowly forgotten outside of the Crescent City. Only the steadfast amateur investigators of the JFK conspiracy kept going over Garrison's weird case, until a frantic and talented Hollywood director decided Garrison would be the hero of a big-budget movie that would destroy the "official story" forever. When Oliver Stone's JFK opened in 1991, at the tail end of the Reagan Era and with an old CIA man from Texas still in the White House, the "mainstream media" was as outraged as ever. The New York Times railed against the movie and all but demanded Warner Bros. tighten the leash on Stone, before the film was even released. Time and Newsweek and the Washington Post did hit pieces.

"Never before in the history of movies has a film been attacked in first draft screenplay form," Stone told Roger Ebert in November 1991. "All the established media seem to be terrified of my movie; as if it's somehow going destroy their lives. I'm amazed at their fear. What stake do they have in it?"

Moviegoers ignored the propaganda and loved JFK. It earned $205 million in theatrical release, in 1991-1992 dollars, and the conspiracy thriller was so convincing that voters demanded new investigations and the release of more assassination papers. The President John F. Kennedy Assassination Records Collection Act of 1992 was a direct result of the film's success, although the CIA managed to shield its own assassination papers from the new law for the usual reasons of "national security."

My mom saved all the newspapers about Kennedy's assassination and its outrageous aftershocks, including the front pages of the Times-Picayune and States-Item with the photographs of Dallas wiseguy Jack Ruby murdering an Oswald in the Dallas police headquarters after cops there walked him into a mob gathered to see the president's killer. I used those newspapers for my third grade history report, a big photo album full of grainy pictures of death and craziness.

Ruby had met with New Orleans mob boss Carlos Marcello, who openly talked of murdering President Kennedy, days before the assassination in Dallas. Proving you can never get away from a conspiracy once you're aware of it, Marcello's grandson was in my third grade classroom. This Sicilian scion had been transferred to my grim, little-known Lutheran parochial school to keep him from being kidnapped from the city's Catholic schools where a Marcello would otherwise go.

The Marcello Family had its tentacles in everything from drugs to hookers, Cuban casinos, local cardrooms, and pinball bars. Carlos himself appeared before the Senate committee on organized crime in 1959, a hearing memorably fictionalized in The Godfather. Robert Kennedy was the committee's chief counsel; his brother John was on the committee itself.

As attorney general and president two years later, the Kennedy brothers ordered the CIA to catch Marcello in Central America, but Marcello always got away and somehow returned to Louisiana, where he operated in daylight until finally being sent to prison in the 1980s in a corruption probe that hit the highest levels of Louisiana government.

Two decades later, when a Texas judge was assassinated in 1979 by one of the alleged "three tramps" led away by police after JFK's murder in Dealey Plaza, the Marcello machine that ordered the hit was already coming apart. The "tramp" convicted of the murder was Charles V. Harrison, father of actor Woody Harrelson, who starred as a media-sensation murderer in Oliver Stone's next movie after JFK. The elder Harrison claimed to be part of the president's assassination team, although he later blamed the admission on cocaine. This stuff can make your head spin.

The reason I went to a cheap Lutheran school was because of the long and intentionally drawn out work of the New Orleans public school board, which had been forced by the federal government to desegregate its schools. A brave little girl named Ruby Bridges was led through a gauntlet of screaming racist cretins on November 14, 1960, and William Frantz Elementary became the first "white school" of New Orleans with a black student, even if she took classes by herself surrounded by U.S. marshals. This is the painful scene portrayed in John Steinbeck's Travels With Charley and Norman Rockwell's saddest painting, which now hangs in the White House.

That school, in the Ninth Ward, sits directly across the street from Lee Harvey Oswald's first home at 2109 Alvar Street, because that's how it goes in the United States of Coincidence.

The third school to be desegregated was T. J. Semmes elementary, in 1963. That was where I began kindergarten not so many years later, down the block from my grandparents' double-shotgun house in the Lower Ninth Ward. John F. Kennedy was the reason I was there, in a neighborhood that most people, white and black, hoped to escape. Kennedy had vowed to put a man on the moon, to show those dirty communists in Russia, and by the middle 1960s both of my parents worked for NASA in Texas. With Kennedy long dead and the space show over and most everyone at NASA laid off, we were back in the Lower Nine.

By 1973, the year Jim Garrison lost to Harry Connick Sr., the school board's racist plan had stripped New Orleans' public schools of most local and state funding and sent working-class white families running from their old neighborhoods.

I was at another public school by then, my parents having finally saved enough to get their own place, and I remember the day the buses came with kids from the notorious Desire housing projects. Those kids had been kept sitting on the bus in the broiling heat for an hour or more. They were disgusted and angry, they knew about the cruelty endured by the first black children to attend the white schools, and for obvious reasons of intentional chaos a bunch of big kids who should've been in sixth grade were pushed into my classroom of eight-year-olds and told to sit down in those tiny chairs with the attached desktops. There was a stabbing—something minor, with a pen knife—but it was enough to send the remaining white kids and the better-off black kids to whatever bottom-of-the-barrel private school their parents could afford.

There is a paranoid style to American popular culture because the reality of our commerce and government is so tawdry, so far below the ideals we're taught in grade school—ideals that were only ever taught to keep us in line, anyway. We are paranoid in America and we're paranoid with good reason. White people in power, meeting behind closed doors, really did conspire to destroy the New Orleans public schools, and they succeeded. Mob bosses really did run New Orleans and Dallas. Presidents really did get assassinated in America, again and again, and there are always rival factions ready to take advantage of chaos and bloodshed.

But we are also dumb romantics. JFK wasn't going to save us from Vietnam any more than Obama saved us from the War on Terror or Clinton saved us from Reaganomics or Reagan saved us from the New Deal and the Civil Rights Act. The strangest and most fitting fact about the last 50 years in America is that the only president who really accomplished anything good was Richard Nixon, a pasty sleazebag so unloved that not even his biggest supporters ever felt romantic about him.

A conspiracy theory offers hope, the belief that if the truth was ever known, if the bad guys ever got caught, then we would all be on a very different path. Jim Garrison believed this, and maybe Lee Harvey Oswald did, too.

Ken Layne marks the nation's holidays and anniversaries in his American Almanac. Illustration by Jim Cooke.