Marijuana Prohibition Began With These Arrests in 1937

Published on October 2, 2017 · Last updated July 28, 2020

Editor’s Note: This week marks the 80th anniversary of the Marihuana Tax Act of 1937, which went into effect on October 1, 1937. To mark four decades of cannabis prohibition, Leafly is reposting Dan Glick’s feature on Moses Baca and Samuel Caldwell, the first two Americans arrested in the federal government’s eight-decade war on cannabis. Dan’s article was originally published by Leafly in December, 2016. 

The first thing you notice about the mug shot of Samuel R. Caldwell is that the man is wearing overalls. The balding, middle-aged Caldwell’s brow is furrowed, his lips tightly pursed. “Colo State Pen 18699” hangs around his neck, snug to the top of his tightly cinched denim shoulder straps. His eyes stare defiantly into the prison photographer’s lens, just shy of seething. A few years after the photo was taken, the serially incarcerated Caldwell would be picked up by police at a Denver flophouse and sent to federal prison in Leavenworth, Kansas. There he served four years for an act that had become a federal crime just a few days before his arrest on October 5, 1937: selling marijuana.

In the decades since, Caldwell has become an unlikely poster child for cannabis legalization advocates. His mug shot adorns t-shirts, posters, and coffee cups canonizing Caldwell as “The First Pot POW.” Although Caldwell was undeniably early collateral damage in America’s war on drugs, his story isn’t a straightforward march to marijuana sainthood. In fact, it’s quite messy.

Sam Caldwell has long been enshrined as the iconic 'first pot POW.' But in fact he was not the first.

A laborer with an 8th grade education and a lengthy rap sheet, Caldwell was hardly the innocent farmer that his overalls might suggest. He was, in the words of one of his prison evaluations, a “career criminal” and former bootlegger who owned more than just the four pounds of cannabis found in his Lothrop Hotel room on Denver’s Laurence Street. Caldwell also possessed a comically bad sense of timing. According to one of his friends, the 57-year-old Caldwell had only begun selling marijuana a few months before the new federal law kicked in. It was a pure financial play—he never smoked the stuff. Four years earlier, in January 1933, federal agents arrested Caldwell for selling a gallon of contraband whiskey for $5—less than a year before the 21st Amendment overturned Prohibition. Caldwell’s first tour in Leavenworth was for peddling white lightning, not Panama Red.

This much is true: Sam Caldwell was one of the earliest targets of the 1937 Marihuana Stamp Act. But in point of fact, he was not the first.

Moses Baca's arrest report: 3:15 a.m., October 3, 1937.
Moses Baca's arrest report: 3:15 a.m., October 3, 1937.

Moses Baca: A dashing ne’er-do-well

Moses Baca’s marijuana arrest, two days before Caldwell’s in a different Denver neighborhood, should have earned him the top spot in the Cannabis Hall of Fame. In Baca’s only known criminal justice shot, the 23-year-old looks a little like a Mexican-American version of Prince, with a shock of unruly hair, a few wisps of mustache, full unparted lips and a thousand-mile stare. A Colorado State Reformatory number, 8755, sits on his right breast, and he’s sporting a striped shirt under a ratty sport coat.


Moses Baca in 1935, two years prior to his cannabis bust.

Despite the fact that the new federal law had been aimed at “peddlers” rather than users, Baca’s crime was to possess a mere quarter ounce of the evil weed. Police found it in a bureau drawer in his third-floor rooming house on California Street in Denver’s Five Points neighborhood as they were arresting him on a “Drunk & Disturbance” charge.

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As the folk hero status of Caldwell and Baca grew with the cannabis reform movement, the two began being erroneously linked as buyer and seller of those first federal joints. Facts, as they say, should never get in the way of a good story.

Moses Baca was arrested two days before Caldwell, at 3am on a Sunday morning in Denver's Five Points neighborhood.

Like Caldwell, Baca is an unlikely hero of the weed wars, with an even longer rap sheet and an ugly propensity to beat his wife. As a man of Mexican heritage (he was born in southern Colorado), Baca fit the profile of the kind of person legislators were targeting when Congress passed the first federal marijuana law. Still, he got off easier than Caldwell on his marijuana charge: Baca served less than 18 months, also in Leavenworth.

The all-too obvious irony of these men’s stories, gleefully seized upon by the modern cannabis reform movement, is that both jailbirds were popped for pot in the same state that would be the first in the Union to legalize it, 76 years later. Today any adult visiting Colorado can do with impunity what, in a less urbane form, sent Caldwell and Baca to federal prison: purchase some Sour Diesel and pleasurably imbibe.

Uncle Mike takes up the case

Much as I wish it were so, I can’t claim to be the sleuth who uncovered the full truth about Caldwell and Baca. That title falls upon a 48-year-old drug felon and autodidactic cannabis historian who goes by the pen name “Uncle Mike.” It was he who spent years digging through documents and posting them on an obscure website—www.UncleMikesResearch.com—and it was he who earned nothing from his efforts but a visit from a nosy reporter. 

Activist and historian “Uncle Mike” (a pseudonym) holds a 20-year-old folder stuffed with research on Baca, Caldwell, and the early years of America’s war on cannabis. The folder has become a historical document in its own right. “I’m one of those people who starts using something, can’t get rid of it,” he said. (Daniel Brenner for Leafly)

I read the Caldwell-and-Baca stories a few years ago, when Colorado’s first retail stores opened and the Denver Post put them back on the front page. But then I kept catching glances of Caldwell, in all his slick-pated glory, here and there as the legalization movement continued to expand across America. And it made me wonder: What’s that dude’s story?

The sleuth who uncovered the truth about Baca and Caldwell is a self-taught historian and proud cannabis felon.

Which, of course, led me to Uncle Mike.

It took me many tries to reach him. Uncle Mike is not a publicity hound. When he finally returned my messages he was wary. So many journalists had screwed up Caldwell and Baca’s story that he was reluctant to do anything at first besides point me to his own research. At the University of Colorado law library, I perused a copy of his book, “U.S. District Court, Denver, Colorado, Imposes First Federal Marihuana Law Penalties: Compilation of Publications, Interviews, Criminal Files and Photographs of Moses Baca & Samuel Caldwell,” © 2008.

Despite the unwieldy title, the book proved to be a treasure chest of material. I was gobsmacked by the primary documents Uncle Mike had obtained: microfiche copies of arrest records, court documents, newspaper clippings, handwritten interview notes, Congressional testimony, even the address of the Denver Victorian where Moses Baca had been living when he was arrested. After a series of emails, Facebook messages, and guarded phone conversations, Uncle Mike finally agreed to guide me through the morass of half-truths, mistaken identity, and fuzzy storytelling emerging from both sides of the marijuana divide. But only over the phone. There would be no face-to-face meeting. At least not for now.

His arrest is a badge of honor

Uncle Mike calls himself “just a redneck from Craig,” a rural Colorado town more well known for being a hardscrabble coal community than it is for breeding cannabis activists. After a lifetime living in the underground, he still isn’t comfortable using his real name. He lives in a state that legalized the source of his paranoia four years ago, but legality hasn’t swept away the suspicion. He remembers when he was first gathering signatures for a Colorado hemp initiative in the late 1990s, “I couldn’t get potheads to sign, dude,” he told me. “They all thought that narcs would get the list.” Old habits die hard.

Uncle Mike was born in 1968 and found his way into political activism the hard way: in handcuffs. A hometown bust for “pot and acid” gave him a taste of prison. “It’s a pre-requisite for being a hardcore activist,” he told me. “After experiencing the system, you’re really pissed off.” He did his time and eventually came to see his arrest as a badge of honor shared with many other reformers; a victim, like Caldwell and Baca, of being born in the wrong era.

Fallacies about Baca and Caldwell were repeated so often they became worse than urban myths. They became fact.

After getting out of the joint, Uncle Mike started reading history and began writing a book about the marijuana resistance. That’s when he stumbled onto the Caldwell and Baca story. The facts seemed jumbled, the historians a bit over-reliant on a couple blatantly inaccurate newspaper stories. Those reports had Caldwell selling three joints to Baca; they botched the dates and sequence of the arrests; they got Caldwell’s age wrong (57, not 58) and Baca’s age wrong (23, not 26); they frequently gave Caldwell first billing in the historic arrest sweepstakes, and they reprinted unquestioned assertions from law enforcement about the “devil weed.”

As marijuana propaganda campaigns raged over the decades, Caldwell and Baca’s unfortunate circumstances were teed up as cannon fodder. Quotes were fabricated, conspiracy theories launched. When medical marijuana was approved by voters in Colorado in November 2000, Denver Post and Rocky Mountain News reporters searched their papers’ morgues to unearth tales of 1937-style justice. The fallacies were repeated so often they became worse than urban myths. They became fact.

So Uncle Mike dug in. During a two-year period while he was collecting unemployment insurance, he hitchhiked around the country to places like Pennsylvania State University, which houses the papers of Harry J. Anslinger, first commissioner of the Federal Bureau of Narcotics. By scrounging through federal archives and hounding Denver law enforcement officials, he compiled the goods to set the record straight. “I had no idea that you couldn’t trust what you read, dude,” he told me.

“Its use is spreading to all classes.”

The 1937 Marihuana Stamp Tax Act was a solution in search of a problem. The repeal of alcohol Prohibition in 1933 led to an urgent search for new moral ground to exploit. Marijuana made an excellent target, since a number of Western state politicians were raising a ruckus in Washington D.C. about its use. In the New York Timeson Sept 16, 1934, a headline warned “Use of Marijuana Spreading in West: Children said to Buy It,” with this dog-whistle admonition: “Although as appalling as its effects on the human mind and body as narcotics, the use of marihuana appears to be proceeding unchecked in Colorado and other Western States with a large Spanish-American population. The drug is particularly popular with Latin Americans and its use is spreading to all classes.” 

Federal narcotics chief Harry J. Anslinger led a personal crusade against cannabis for 32 years.

Most historians agree that racism factored heavily into America’s drug laws. Yale historian David F. Musto put it this way: “The anti-marihuana law of 1937 was largely the federal government’s response to political pressure from enforcement agencies and other alarmed groups who feared the use and spread of marihuana by ‘Mexicans.’” 

The approach began with Anslinger and continued for decades. In the early 1970s, President Richard Nixon used drug laws to target his political enemies, which included Jews, liberals, and hippies. In an interview with Nixon advisor John Ehrlichman that appeared in a Harpersarticle this past April, author Dan Baum quoted the Watergate co-conspirator and convicted felon:

“You want to know what this [the War on Drugs] was really all about?” [Ehrlichman] asked with the bluntness of a man who, after public disgrace and a stretch in federal prison, had little left to protect. “The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and black people. You understand what I’m saying? We knew we couldn’t make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin, and then criminalizing both heavily, we could disrupt those communities. We could arrest their leaders, raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did.”

Anslinger and his anti-drug cronies also needed a Big Lie, since they were having a hard time getting Congress to outlaw a weed that Anslinger himself acknowledged grew wild with great abandon. So legislation focused on the sale of weed, craftily using the same Catch-22 logic of a Prohibition-era gun control law. 

The violence-ridden era of Al Capone had given birth to a federal law to curb the unlawful sale of Tommy Guns, long before the NRA would have made this impossible. The National Firearms Act of 1934 declared that anybody who sold a machine gun had to have a stamp, printed by the federal government, sanctioning the sale. Then the government failed to print the stamp. 

Anslinger's cannabis stamp tax came with a catch: You'd be arrested if you tried to buy a stamp.

The same diabolical construction was put to use in the new marijuana law. People could legally sell cannabis as long as they purchased a marihuana tax stamp. There were only two catches. First, you had to show up with your cannabis in order to purchase the stamp, which would trigger an arrest on illegal possession charges. Second, nobody really knew if the stamps existed or where you could buy them. This unconstitutional logic finally caught up with the feds in 1969, when drug guru Timothy Leary successfully challenged the law in a landmark case that unanimously overturned it. The vacuum created by Leary’s case led to the creation of the Controlled Substances Act of 1970.

The 1937 Marihuana Stamp Act passed Congress in early August but didn’t take effect until October. The question became how and where the feds would enforce it. One clue comes from an article that Uncle Mike found in the Denver Post, dated August 8, 1937 with the headline “U.S. Narcotics Bureau Plans Marijuana War: Drive in Western States Planned with New Act Passed.”

As the biggest Western city for almost seven hundred miles in any direction, Denver was an ideal choice for a high-profile first bust.

Moses Baca and Mr. X

It’s unclear why Moses Baca was the first one targeted, but it makes sense that he might have been one of the “usual suspects” rounded up by Denver police. Baca was no stranger to the cops.

Thanks to Uncle Mike’s research we have Baca’s FBI files, which act as a bracing illustration of the prevailing 1937 attitudes towards “wetbacks.” The derogatory term, coined in 1929, referred to Mexicans who swam or waded across the Rio Grande to come to the United States. Baca is listed as 5’7 ½”, 130 pounds when he is first arrested at age 16, with a “swarthy” complexion, dark maroon eyes, and “black & curley” [sic] hair. At 17, he was arrested for being part of a trio that stole three suits from a tailor shop while drunk. When Baca was sentenced for a burglary conviction in 1934 at the age of 20, the police report states that he had been working as a bellhop. In subsequent years, he was arrested for vagrancy (dismissed), burglary, and larceny. The rap sheet goes on: wanted for assault and robbery, then “no longer wanted,” then more vagrancy, and multiple arrests for drunk and disorderly conduct. His race was often listed as “Mexican.”

Denver police warned Mr. X: Don't hang out with Mexicans.

According to Denver Police records, Baca was arrested at 3:15 a.m. on Sunday, October 3, 1937. Police wrote: “This man came home drunk and beat his wife.” During that early Sunday morning premises search, the cops turned up the quarter ounce of cannabis. Anslinger would later concoct a story that Baca had been involved in “gun play,” which doesn’t show up in any of the police reports. Nor does any record confirm a story, floated by the Denver Post, that Baca blamed his violence on marijuana. “Under its influence [Baca] said, he became a wild beast, and two weeks ago tried to murder his wife, the mother of his three children.”

To Uncle Mike, that “wild beast” bit smacked of classic Reefer Madness propaganda, and it fueled his quest to find the truth. Digging around in old copies of the Pikes Peak Hemp Coalition newsletter, he turned up a 1996 piece about a man in his mid-seventies who had been busted for pot in Denver in the late 1930s.

The man, identified as “Mr. X,” confirmed that police were clearly targeting people like Baca. The police warned Mr. X., “Don’t hang out with Mexicans.” Uncle Mike tracked down Gregory Dauerer, author of the Hemp Coalition piece, who revealed Mr. X’s identity—Alexander Rahoutis, who died in 2002. Daurer offered Uncle Mike the notes from his interview.

He was no angel: Sam Caldwell’s rap sheet included check fraud, bootlegging, burglary, and “running disorderly house.” Document courtesy of Uncle Mike.

In the notes, Rahoutis said he knew both Baca and Caldwell. Rahoutis had “business” dealings with Caldwell, who was an unemployed laborer from Indiana with a record for writing bad checks and bootlegging. At the time of his arrest, Caldwell was staying at Denver’s Lothrop Hotel, a transient flophouse. According to Rahoutis, Caldwell never smoked marijuana himself and hadn’t sold Baca “a goddamned thing.”

As for Baca, Rahoutis recalled he was known to use cocaine and drink Sterno, an alcohol-based fuel used to heat food. Known as “canned heat,” Sterno was sometimes consumed as a low-budget high, with side effects that included violent behavior, hallucinations, and sometimes death. It’s a lotmore likely that Sterno, not cannabis, accounted for Baca’s violent behavior. But in October 1937, Sterno was legal. Cannabis was not.

Harry J. himself shows up for sentencing

Anslinger was so passionate about the implementation of the 1937 Marihuana law that he traveled to Denver from Washington D.C.—a two-day trip by rail—in order to attend the trial and sentencing of both Caldwell and Baca. Newspaper reports from the time indicated that Anslinger was “between trains” in Denver and stuck his head in the courtroom, which almost certainly understates Anglinger’s calculated appearance. He understood the propaganda value of those first arrests. After sentencing, Anslinger went out of his way to praise the prosecutors. “These men have shown the way to other district attorneys thruout [sic] the nation,” he told the Denver Post. “Marijuana has become our greatest problem. Its sale and use has found its way into at least twenty-five states.”

Following the sentencing of Baca and Caldwell, Anslinger went on a reefer madness press tour. He told the Minneapolis Journal, here, that cannabis turned children into “murderous criminals.”

Today, 28 states and the District of Columbia have legalized marijuana use in some form, and to hear U.S. District Court Judge J. Foster Symes’ 1937 pronouncement for the press (and Anslinger) seems even more ludicrous now than it must have seemed then: “I consider marijuana the worst of all narcotics, far worse than the use of morphine or coca

“I have no sympathy with those who sell this weed,” said the judge.

Under its influence men become beasts. Marijuana destroys life itself. I have no sympathy with those who sell this weed. The government is going to enforce this new law to the letter.” 

A glowing profile of Anslinger in the Washington Times with the doting headline, “I Work for Uncle Sam” later reported that he had attended the proceedings “incognito” and took “great pleasure” from the outcome.

The scene of the crime today 

On a hot July day in Denver, Uncle Mike agreed to meet me at the house where Moses Baca was arrested on that fateful October day. Curtis Park, once Denver’s only welcoming African-American neighborhood, is now a trendy, up-and-coming hipster zone. Baca’s pad is currently being renovated.

Uncle Mike was excited to revisit the scene of the crime. He’s lanky, with a long bouncing ponytail, oval eyeglasses, and a salt-and-pepper beard. A few years ago he had met the owner, Michael Ritchie, and gave him a copy of his Baca research. Ritchie owns an architectural salvage business and several other houses on the block.

Uncle Mike smokes a joint outside Moses Baca’s former residence, 2625 California Street in Denver, Colorado, in December, 2016. (Daniel Brenner for Leafly)

Ritchie cheerfully guided us up to the third floor, where Baca holed up at the time of his arrest. The 1884 house was originally built by a wealthy Denver businessman and declined into a rooming house as it aged. When Ritchie bought the house he was unaware of the Baca connection. Once he found out, he included the fun fact as part of a historical house tour brochure. Ritchie handed me a copy, which stated that the house attained some notoriety “when one of its occupants was one of two men arrested for marijuana. They became the first men in the country to be sentenced to prison terms under a brand new federal anti-marijuana law.” Uncle Mike is pleased that the brochure, although lacking detail, gets it right.

We finally entered the room where the historic bust occurred. Uncle Mike was visibly jazzed. “So this is the Baca pad,” he said, almost dreamily. He stood still to take in every detail.

Baca’s rented room was in Denver’s Five Points neighborhood, a hip happening place in the 1930s. Here, Uncle Mike climbs the stairs to the Baca house’s rooftop viewpoint. (Daniel Brenner for Leafly)

Up on the roof, the three of us took in a sweeping view of the Rocky Mountains. Below us the neighborhood of Curtis Park, Ritchie explained, was once the heart of Five Points, the most hopping place in Denver back in the day. Here were jazz clubs, a diverse demographic, and no small amount of history. Ella Fitzgerald, Duke Ellington, and Nat King Cole played in the nearby clubs. Jack Kerouac’s sidekick Neal Cassidy’s father, who appears as a bit character in On the Road, worked at a local barbershop. Upon hearing Ritchie’s reference to On the Road, Uncle Mike exclaimed: “That’s the first book I ever read in jail!”

From arrest to prison in two weeks flat

So, with Uncle Mike’s help, let’s set the record straight.

The Marihuana Stamp Tax Act was approved on August 2, and went into effect on October 1, 1937. Moses Baca was arrested in the wee hours of October 3; Samuel Caldwell was taken in two days later. Both pleaded guilty. Both were sentenced by federal Judge J. Foster Symes on October 8. Baca got 18 months for possessing a quarter-ounce. Caldwell was caught selling three joints—not to Baca but to a fellow named Claude Morgan, whose fate is lost to history—and was also caught in possession of four pounds of cannabis, which he’d smuggled over the state line from Kansas. As a trafficker, Caldwell received a heavier sentence of four years.


Broken man: A less defiant Sam Caldwell during his second stint in Leavenworth. He died shortly after his release in 1941.

On October 17, 1937, both were received at the United States Penitentiary in Leavenworth, Kansas. The wheels of justice turned swiftly in the 1930s. Baca and Caldwell were whisked from the streets of Denver to the wards of Leavenworth in less than two weeks.

Samuel Caldwell served nearly all of his sentence. He was released in early 1941 and died on June 24 of that year, at the age of 61. The cause of death was liver cancer, which is often linked to excessive drinking. He was buried in Erie, Colorado, about 25 miles north of Denver. 


Moses Baca’s gravestone in California. Photo by Andrew Garret.

The feds sprung Moses Baca after 14 months. By March 1939, Baca was back in Denver and up to no good. Police records indicate he was picked up on a car prowl charge, and various 3 a.m. drunk-and-disorderlies, through 1940. He picked up work as a shipfitter and painter at various West Coast ports during the war, eventually settling in Los Angeles. Baca died in California on March 19, 1948, at the age of 33. His cause of death is listed as “overwhelming toxemia,” or blood poisoning. On Baca’s death certificate, his race is listed as “White.” 

As for Anslinger, he stuck at his job until 1962, when he retired at age 70. He died in 1975, almost exactly halfway between the passage of the first federal pot law and Colorado’s vote to legalize its recreational use.

Despite the trend toward legalization, marijuana arrests continue to pad crime statistics. In 2014, more than 620,000 Americans were arrested for simple pot possession, which works out to be more than one per minute. Between 1995 and 2014, more than a half million people were arrested each year for marijuana, mostly for possession, a number that’s understated since not all states report all their stats to the FBI. The casualty count that began with Baca and Caldwell continues to mount, with collateral damage also inflicted on millions of people like Uncle Mike, who remains haunted by his felony conviction every time he looks for work.

The casualty count that began with Baca and Caldwell continues, with collateral damage inflicted on people like Uncle Mike, who remains haunted by his felony conviction every time he looks for work.

The “last soldier to die” has come to represent the futility of war itself, as John Kerry (now Secretary of State, then an outspoken anti-war veteran) told a congressional committee in 1971 about the pointlessness of the Vietnam War. “How do you ask a man,” he said, “to be the last man to die for a mistake?”

Thanks to Uncle Mike and other legalization advocates, Moses Baca and Samuel Caldwell continue to be recognized as the first casualties in America’s 79-year war on cannabis. They were the first. It may be many years before we are able to identify the last.

After our tour of Baca’s abode, Uncle Mike and I strolled to a neighborhood coffee shop to muse. Four recreational cannabis shops sat within walking distance of our table. Uncle Mike gazed out the window and wagged his ponytail in disbelief. “After some of the shit we’ve gone through over the years, dude, I never thought I’d live to see legalization,” he said. Even though there are legal shops everywhere, he’s only been to a recreational store once, to experience it with his adult son. Uncle Mike still prefers to grow his own.

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Daniel Glick
Daniel Glick
Daniel Glick is co-founder of The Story Group and author of Monkey Dancing: A Father, Two Kids, and a Journey to the Ends of the Earth. He was formerly a Washington, DC, correspondent for Newsweek and has written for more than 50 national and international publications. He lives in Colorado.
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