In today's incredibly fraught political atmosphere, bipartisanship feels more like a term in the history books than a possibility in Congress.
Sarah Palin, whom McCain plucked from obscurity to become his 2008 White House running mate, described him as "an American original" and "a fighter, never afraid to stand for his beliefs".
In July previous year, just after his diagnosis, he took part in a late-night Senate session and gave the deciding vote - with a thumbs-down gesture - against partially repealing the contentious Obamacare healthcare law.
"John McCain was a patriot of the highest order, a public servant of rarest courage". He went on to spoof his reputation as a political maverick by boasting about reducing Arizona's length of paved roadway to less than 900 miles, and forcing residents of the state to drive to New Mexico if they want to mail a letter.
'Mo reached out to me in 50 different ways, ' McCain told Slate in 2008.
'All these journalists would show up to hear what Mo had to say.
"Even when your dad got mad at me, said I should get the hell of the ticket, and remember what I said about your dad?" Well, hell, I didn't have any views.
McCain represented Arizona since 1982, first at the House of Representatives for two terms and then at the Senate for more than three decades - since 1986, during which he twice sought the presidency. 'And there was no reason for him to be that way'.
McCain narrowly avoided drowning, but his rescuers took him as a prisoner of war at the Hoa Lo Prison, which earned the infamously ironic nickname the "Hanoi Hilton".
The senator would always come with a stack of newspaper clips to read to his mentor, specifically selected to match Udall's favorite subjects.
But together they worked on helping to restore America's relations with Vietnam.
A "spirt of service and civility" guided McCain's life, standing as a model for Americans regardless of political affiliation, Ducey said.
Former US presidents will likely be at McCain's funeral - but Trump probably won't.
'I will be grateful for that lesson every day of my life'.
'You have my respect and admiration, ' he said in a direct address to Obama at the Republican National Convention. "It was there that he made the most difference". "We don't need more bullying, and I'm exhausted of it!"
He backed the 2003 invasion of Iraq and criticised President Obama for not intervening more in the Syrian civil war.
The grim prognosis didn't appear to immediately slow down McCain who kept a robust schedule and didn't hold back his pointed criticism of President Donald Trump. McCain, however, fought for what he believed was right until the very end.
'To fear the world we have organized and led for three-quarters of a century, to abandon the ideals we have advanced around the globe, to refuse the obligations of global leadership and our duty to remain "the last best hope of Earth" for the sake of some half-baked, spurious nationalism cooked up by people who would rather find scapegoats than solve problems, is as unpatriotic as an attachment to any other exhausted dogma of the past that Americans consigned to the ash heap of history, ' he said a year ago in Philadelphia.
Sources quoted by USA media said Mr Trump would not be invited to the funeral and the current administration would probably be represented by Vice President Mike Pence.
The ticket failed to gain lasting traction in the face of an inspiring Obama campaign, especially following a financial crash in the fall of 2008 while George W. Bush was president.