Following Sean's birth in 1975, Lennon took a hiatus from the music industry and became a stay-at-home dad to care for his infant son.
He resumed his songwriting career shortly before his December 1980 murder, which Ono witnessed at close range.
She stated the couple was thinking about going out to dinner after spending several hours in a recording studio, but decided to return to their apartment instead, because Lennon wanted to see Sean before he was put to bed.
Following her husband's murder, Ono went into complete seclusion for an extended period.

Ono funded the construction and maintenance of the Strawberry Fields memorial in Manhattan's Central Park, directly across from the Dakota Apartments, which was the scene of the murder and remains Ono's residence to this day.
It was officially dedicated on October 9, 1985, which would have been his 45th birthday.
In 1990, Ono collaborated with music consultant Jeff Pollack to honor what would have been Lennon's 50th birthday with a worldwide broadcast of Imagine.
Over 1,000 stations in over 50 countries participated in the simultaneous broadcast.
Ono felt the timing was perfect, considering the escalating conflicts in the Middle East, Eastern Europe, and Germany.

In 2000, she founded the John Lennon Museum in Saitama, Japan.
In March 2002, she was present with Cherie Blair at the unveiling of a seven-foot statue of Lennon to mark the renaming of Liverpool airport to Liverpool John Lennon Airport. (
Julian and Cynthia Lennon were present at the unveiling of the John Lennon Peace Monument next to ACC Liverpool in the same city eight years later.)
On October 9, 2007, she dedicated a new memorial called the Imagine Peace Tower, located on the island of Viðey, 1 km outside the Skarfabakki harbour in Reykjavík, Iceland.
Each year, between October 9 and December 8, it projects a vertical beam of light high into the sky.
In 2009, Ono created an exhibit called "John Lennon: The New York City Years" for the NYC Rock and Roll Hall of Fame Annex.
The exhibit used music, photographs, and personal items to depict Lennon's life in New York.
A portion of the cost of each ticket was donated to Spirit Foundation, a charitable foundation set up by Lennon and Ono.

Every time Lennon's killer Mark David Chapman has a parole hearing – which is mandated by law every two years – Ono has come out strongly against his release from prison.
Following Sean's birth in 1975, Lennon took a hiatus from the music industry and became a stay-at-home dad to care for his infant son. He resumed his songwriting career shortly before his December 1980 murder, which Ono witnessed at close range. She stated the couple was thinking about going out to dinner after spending several hours in a recording studio, but decided to return to their apartment instead, because Lennon wanted to see Sean before he was put to bed. Following her husband's murder, Ono went into complete seclusion for an extended period.
Ono funded the construction and maintenance of the Strawberry Fields memorial in Manhattan's Central Park, directly across from the Dakota Apartments, which was the scene of the murder and remains Ono's residence to this day. It was officially dedicated on October 9, 1985, which would have been his 45th birthday. In 1990, Ono collaborated with music consultant Jeff Pollack to honor what would have been Lennon's 50th birthday with a worldwide broadcast of Imagine. Over 1,000 stations in over 50 countries participated in the simultaneous broadcast. Ono felt the timing was perfect, considering the escalating conflicts in the Middle East, Eastern Europe, and Germany.
In 2000, she founded the John Lennon Museum in Saitama, Japan. In March 2002, she was present with Cherie Blair at the unveiling of a seven-foot statue of Lennon to mark the renaming of Liverpool airport to Liverpool John Lennon Airport. (Julian and Cynthia Lennon were present at the unveiling of the John Lennon Peace Monument next to ACC Liverpool in the same city eight years later.) On October 9, 2007, she dedicated a new memorial called the Imagine Peace Tower, located on the island of Viðey, 1 km outside the Skarfabakki harbour in Reykjavík, Iceland. Each year, between October 9 and December 8, it projects a vertical beam of light high into the sky. In 2009, Ono created an exhibit called "John Lennon: The New York City Years" for the NYC Rock and Roll Hall of Fame Annex. The exhibit used music, photographs, and personal items to depict Lennon's life in New York. A portion of the cost of each ticket was donated to Spirit Foundation, a charitable foundation set up by Lennon and Ono.
Every time Lennon's killer Mark David Chapman has a parole hearing – which is mandated by law every two years – Ono has come out strongly against his release from prison.
Yoko Ono