[6]: 4  Chapin's parents divorced in 1950, with his mother retaining custody of their four sons, as Jim spent much of his time on the road as a drummer for Big Band-era acts such as Woody Herman.

[6]: 21–22  Harry's younger brothers Tom and Steve were choirboys at Grace Episcopal Church in Brooklyn Heights, and through them Chapin met "Big" John Wallace, a baritone with a five-octave range, who later became his bassist, backing vocalist, and straight man onstage.

Chapin originally intended to be a documentary film-maker and took a job with The Big Fights, a company run by Bill Cayton that owned a large library of classic boxing films.

With John Wallace, Tim Scott, and Ron Palmer, Chapin started playing in various nightclubs in New York City.

In 1972, there was a bidding war over Chapin between music business heavyweights Clive Davis at Columbia and Jac Holzman at Elektra.

The song was performed on The Tonight Show Starring Johnny Carson, which received so many calls that Chapin returned the next night.

I envisioned some night I'd be driving a cab in the big city streets and this lady would get in the back, and I'd turn and look at her and she'd look at me and know we both sold out our dreams.

The album sold over 1 million units and produced another international hit, "W.O.L.D.," a song about an aging disc jockey who has given up his entire life and family for his career.

The song "Mr. Tanner" was loosely based on a pair of New York Times concert reviews of baritone Martin Tubridy – once in 1971[10] and once in 1972.

[11] In 1974, Chapin released his most successful album, Verities and Balderdash, which sold 2.5 million units because of the number 1 hit "Cat's in the Cradle."

The album's follow-up single, "I Wanna Learn a Love Song," charted at number 7 on Billboard Adult Contemporary.

In 1975, Chapin released his fifth album, Portrait Gallery, which produced a top-40 Billboard Adult Contemporary hit, "Dreams Go By."

[15] In the mid-1970s, Chapin devoted much time and effort to social activism, including raising money to combat hunger in the United States.

[16] He co-founded the organization World Hunger Year with radio personality Bill Ayres, before returning to music with On the Road to Kingdom Come.

Chapin donated an estimated third of his paid concerts to charitable causes, often performing alone with his guitar to reduce costs.

One report quotes Chapin's widow saying soon after his death – "only with slight exaggeration" – that "Harry was supporting 17 relatives, 14 associations, seven foundations, and 82 charities.

Despite his success as a musician, he left little money and it was difficult to maintain the causes for which he raised more than $3 million in the last six years of his life.

On the afternoon of July 16, 1981, Chapin was driving on the Long Island Expressway en route to perform at a free benefit concert at Lakeside Theater[21] at Eisenhower Park in East Meadow, New York, that evening.

Chapin was immediately taken by helicopter from the crash site outside Jericho, New York, to the nearby Nassau County Medical Center, where he was pronounced dead at 1:05 p.m. due to internal bleeding.

[2][22] Chapin's widow won a $12 million decision in a negligence lawsuit against Supermarkets General, the owners of the truck involved.

During the 24-hour period of the event, little to no music was played, with the exception of the iconic "Alice's Restaurant" by Arlo Guthrie played at noon and 6 p.m. For the remainder of the day, during every DJ's four-hour show, guests such as Harry himself, other music stars, and experts on hunger brought to the listeners information about the severity of hunger in America, in New York City, and in the tri-state area, sometimes in graphic detail.

After Chapin's death, the "Hungerthon" continued, and on July 13, 1985, at the U.S. leg of the Live Aid concert in Philadelphia at JFK Stadium, Kenny Loggins was presented with the first "Harry Chapin Humanitarian Award" by actor Jeff Bridges for his work for the World Hunger League in fighting hunger in America.

Soon after Chapin's death, his estate notified Coan that he must return all materials related to the book and that he "no longer had the rights to the book-in-progress".

[35] On December 7, 1987, on what would have been his 45th birthday, Chapin was posthumously awarded the Congressional Gold Medal for his campaigning on social issues, particularly his highlighting of hunger around the world and in the United States.

In 2001, Chapin's "Cat's in the Cradle" was ranked number 186 of 365 on the Recording Industry Association of America list of Songs of the Century.

On September 27, 2011, former U.S. Representative Alan Grayson wrote an article on the internet publication The Huffington Post about Chapin's song "What Made America Famous".

[36] Singer and songwriter Guthrie Thomas has long publicly stated that Chapin's song "Cat's in the Cradle" is one of the most difficult songs to perform, due to Chapin's masterful guitar playing and his brilliant syncopation of the lyrics, meaning each word must fit perfectly and in time with the playing.

Also, despite seeming social and political differences with Chapin, Dr. James Dobson often quotes the entirety of "Cat's in the Cradle" to illustrate dynamics of contemporary American families.

[37] A children's picture book was created using the lyrics of "Mr. Tanner" and the illustrations of Bryan Langdo; it was published by Ripple Grove Press in May 2017.

They played with him before his solo career took off, and were credited on the albums Greatest Stories Live, Legends of the Lost and Found, and Chapin Music!