In 1941, the 15-year-old Cassady met Justin W. Brierly, a prominent Denver educator. Brierly was well known as a mentor of promising young men and was impressed by Cassady’s intelligence. Over the next few years, Brierly took an active role in Cassady’s life. Brierly helped admit Cassady to East High School where he taught Cassady as a student, encouraged and supervised his reading, and found employment for him. Cassady continued his criminal activities, however, and was repeatedly arrested from 1942 to 1944; on at least one of these occasions, he was released by law enforcement into Brierly’s safekeeping. In June 1944, Cassady was arrested for possession of stolen goods and served eleven months of a one-year prison sentence. He and Brierly actively exchanged letters during this period, even through Cassady’s intermittent incarcerations; this correspondence represents Cassady’s earliest surviving letters. Brierly, a closeted homosexual, is also believed to have been responsible for Cassady’s first homosexual experience.

In October 1945, after being released from prison, Cassady married the 16-year-old LuAnne Henderson. In 1946, the couple traveled to New York City to visit their friend, Hal Chase, another protégé of Brierly. It was while visiting Chase at Columbia University that Cassady met Jack Kerouac and Allen Ginsberg. Although Cassady did not attend Columbia, he soon became friends with them and their acquaintances, some of whom later became members of the Beat Generation. While in New York, Cassady persuaded Kerouac to teach him to write fiction. Cassady’s second wife, Carolyn, has stated that, “Neal, having been raised in the slums of Denver amongst the world’s lost men, [was] determined to make more of himself, to become somebody, to be worthy and respected. His genius mind absorbed every book he could find, whether literature, philosophy or science. Jack had a formal education, which Neal envied, but intellectually he was more than a match for Jack, and they enjoyed long discussions on every subject.”

Carolyn Robinson met Cassady in 1947, while she was studying for her Masters in Theater Arts at the University of Denver. Five weeks after LuAnne’s departure, Neal got an annulment from LuAnne and married Carolyn, on April 1, 1948. Carolyn’s book, Off the Road: Twenty Years with Cassady, Kerouac and Ginsberg (1990), details her marriage to Cassady and recalls him as, “the archetype of the American Man”. Cassady’s sexual relationship with Ginsberg lasted off and on for the next 20 years.

The couple eventually had three children and settled down in a ranch house in Monte Sereno, California, 50 miles south of San Francisco, where Kerouac and Ginsberg sometimes visited. This home, built in 1954 with money from a settlement from Southern Pacific Railroad for a train-related accident, was demolished in August 1997. In 1950, Cassady entered into a bigamous marriage with Diane Hansen, a young model who was pregnant with his child, Curtis Hansen.

Following an arrest in 1958 for offering to share a small amount of marijuana with an undercover agent at a San Francisco nightclub, Cassady served a two-year sentence at California’s San Quentin State Prison in Marin County. After his release in June 1960, he struggled to meet family obligations, and Carolyn divorced him when his parole period expired in 1963. Carolyn stated that she was looking to relieve Cassady of the burden of supporting a family, but “this was a mistake and removed the last pillar of his self-esteem”.

After the divorce, in 1963, Cassady shared an apartment with Allen Ginsberg and Beat poet Charles Plymell, at 1403 Gough Street, San Francisco.

Cassady first met author Ken Kesey during the summer of 1962; he eventually became one of the Merry Pranksters, a group who formed around Kesey in 1964 who were vocal proponents of the use of psychedelic drugs.

During 1964, Cassady served as the main driver of the bus named Furthur on the iconic first half of the journey from San Francisco to New York, which was immortalized by Tom Wolfe’s book, The Electric Kool-Aid Acid Test (1968). Cassady appears at length in a documentary film about the Merry Pranksters and their cross-country trip, Magic Trip (2011), directed by Alex Gibney.

In January 1967, Cassady traveled to Mexico with fellow prankster George “Barely Visible” Walker and Cassady’s longtime girlfriend Anne Murphy. In a beachside house just south of Puerto Vallarta, Jalisco, they were joined by Barbara Wilson and Walter Cox. All-night storytelling, speed drives in Walker’s Lotus Elan, and the use of LSD made for a classic Cassady performance — “like a trained bear,” Carolyn Cassady once said. Cassady was beloved for his ability to inspire others to love life. Yet at rare times he was known to express regret over his wild life, especially as it affected his family. At one point Cassady took Cox, then 19, aside and told him: “[T]wenty years of fast living — there’s just not much left, and my kids are all screwed up. Don’t do what I have done.”

On February 3, 1968, Cassady attended a wedding party in San Miguel de Allende, Guanajuato, Mexico. After the party, he went walking along a railroad track to reach the next town, but passed out in the cold and rainy night wearing nothing but a T-shirt and jeans. In the morning, he was found in a coma by the tracks, reportedly by Anton Black, later a professor at El Paso Community College, who carried Cassady over his shoulders to the local post office building. Cassady was then transported to the closest hospital where he died a few hours later on February 4, four days short of his 42nd birthday.

Cassady has five known children: Robert William Hyatt Jr. (1945), Cathleen Joanne Cassady (1948), Jami Cassady Ratto (1949), Curtis W. Hansen (1950), and John Allen Cassady (1951). Robert, son of Neal Cassady and Maxine Beam, is an artist working in Arvada, Colorado. In February 2017, he was featured in Westword Magazine. Cathleen, known as Cathy, is the mother of the only grandchild Neal met. Cathy, Jami, and John keep a website in memory of their parents and parents’ “beat” friends.