On Friday his family said in an announcement that Mr McCain had decided to stop treatment for the brain cancer he had been battling for over a year.
A statement from the Senator’s office reads: “Senator John Sidney McCain III died at 4:28pm on August 25, 2018.
“With the Senator when he passed were his wife Cindy and their family.
“At his death, he had served the United States of America faithfully for sixty years.”
Mr McCain had been fighting with glioblastoma, which is the most aggressive cancer that begins within the brain, since July 2017.
In mid-April the veteran had undergone a surgery for an internal infection.
He had not been seen at the US Capitol in 2018.
Mr McCain spent the last couple of months of his life in his adopted home state of Arizona, out of the public eye.
In a memoir, which was published in May, the Senator said that he hated to leave the world, but had no complaints.
He wrote: “It’s been quite a ride.
“I’ve known great passions, seen amazing wonders, fought in a war, and helped make peace,”
“I’ve lived very well and I’ve been deprived of all comforts.
“I’ve been as lonely as a person can be and I’ve enjoyed the company of heroes.
“I’ve suffered the deepest despair and experienced the highest exultation.
“I made a small place for myself in the story of America and the history of my times.”
Mr McCain was the chairman of the Senate Armed Services Committee and his colleagues named the $716billion defence policy bill after him.
US President Donald Trump acknowledged his death and wrote on Twitter: “My deepest sympathies and respect go out to the family of Senator John McCain.
“Our hearts and prayers are with you!”
The office of Barack and Michelle Obama also released a statement on the passing of Senator McCain.
The former US President wrote: “John McCain and I were members of different generations, came from completely different backgrounds and competed at the highest level of politics.
“But we shared, for all our differences, a fidelity to something higher – the ideals for which generations of Amricans and immigrants alike have fought, marched and sacrificed.”
More to follow…