Raised primarily by his maternal grandparents in West Orange, New Jersey, Cassidy was later informed of his parents' divorce, which had happened two years prior without his knowledge.

After completing high school, Cassidy pursued acting and music, moving into his father and stepmother's home in Irvington, New York.

Despite the show's success, Cassidy sought to break free from his idol image, leading to a diverse solo music career with hits in the UK and Australia, and a tumultuous life marked by public and personal challenges.

Despite facing health and legal issues later in life, Cassidy continued performing until announcing his retirement in 2017, before his death later that year.

[3] As his parents were frequently touring on the road, he spent his early years being raised by his maternal grandparents in a middle-class neighborhood in West Orange, New Jersey.

After David Cassidy signed with Universal Studios in 1969, Jack introduced him to former table tennis champion and close friend Ruth Aarons, who later found her niche as a talent manager, given her theater background.

[10] After signing with Universal Studios in 1969, Cassidy was featured in episodes of the television series Ironside, Marcus Welby, M.D., Adam-12, Medical Center, and Bonanza.

In the midst of his rise to fame, Cassidy felt stifled by the show and trapped by the mass hysteria surrounding his every move.

At the peak of his career, Cassidy's fan club was larger than that of any other musical group or pop star, including The Beatles or Elvis Presley.

[9] In Australia in 1974, the mass hysteria was such that calls were made to have him deported from the country, especially after the madness at his 33,000-person audience concert at Melbourne Cricket Ground.

[20][21] A turning point in Cassidy's live concerts (while still filming The Partridge Family) was a gate stampede at the penultimate show on a world tour, in London's White City Stadium on May 26, 1974, when nearly 800 people were injured in a crush at the front of the stage.

Out of respect for the family and to avoid turning the girl's funeral into a media circus, Cassidy did not attend the service, although he spoke to Whelan's parents and sent flowers.

[26] By this point, Cassidy had decided to quit both touring and acting in The Partridge Family, concentrating instead on recording and songwriting.

International success continued, mostly in Great Britain, Germany, Japan and South Africa, when he released three well-received solo albums and several hit singles on RCA in 1975 and 1976.

A decade later, the successful Fox series 21 Jump Street used the same plot, with different youthful-looking police officers infiltrating a high school.

[28] In 1985, music success continued with the Arista release of the single "The Last Kiss" (number six in the United Kingdom), with backing vocals by George Michael, which was included on the album Romance.

These went gold in Europe and Australia, and Cassidy supported them with a sellout tour of the United Kingdom, which resulted in the Greatest Hits Live compilation of 1986.

In 1981, he toured in a revival of a pre-Broadway production of Little Johnny Jones, a show originally produced in 1904 with music, lyrics, and book by George M. Cohan.

However, Cassidy received negative reviews, and he was replaced by another former teen idol, Donny Osmond,[30] before the show reached Broadway.

[citation needed] In 1998, he had an adult contemporary music hit with "No Bridge I Wouldn't Cross" from his album Old Trick New Dog on his own Slamajamma Records label.

[37] In 2000, Cassidy wrote and appeared in the Las Vegas show At the Copa with Sheena Easton, as both the young and old versions of the lead character, Johnny Flamingo.

[38] He co-starred alongside his half-brother Patrick in a short-lived 2009 ABC Family comedy series titled Ruby & the Rockits, a show created by Shaun.

In August 2016, Cassidy performed in The Villages, Florida, and brought multiple attendees to the side of the stage, asking and answering questions and engaging with members of the community who had been fans for nearly half a century.

[52][53] In August 2013, Cassidy's Los Angeles publicist confirmed that the couple had separated, with Shifrin filing for divorce in February 2014.

[55][56][57] In 2011, Cassidy recorded a public service announcement for Alzheimer's disease research and prevention – because his mother, Evelyn Ward, suffered with the condition[58] – and said that he would campaign for that cause whenever possible.

During a 2012 guest appearance on The Colbert Report he expressed his views on the leading Republican candidates for president, Mitt Romney and Newt Gingrich.

[65][66] Cassidy was arrested on suspicion of DUI in California on January 10, 2014, after he made an illegal right turn against a red light.

[68][69] On September 9, 2015, Cassidy was cited in Fort Lauderdale, Florida, on charges of leaving the scene of a car accident, improper lane change, expired plates and driving on a suspended license.

[74] Cassidy also acknowledged that there was "no sign of [dementia] at this stage of [his] life," adding that "[it] was complete alcohol poisoning—and the fact is, I lied about my drinking.

[4] In December 2019, C'mon, Get Happy was published as an E-book (by Open Road Media, ISBN 0446395315) with a new afterword by Chip Deffaa, covering the rest of Cassidy's life.