1. He was born in Panama
John Sidney McCain III was born at a naval station in the Panama Canal Zone, which was under U.S. control at the time. He comes from a family of naval officers - both his father and grandfather served.
2. He was almost killed by a fire during his service in Vietnam
McCain joined the navy as a pilot, and is well known for his service during the Vietnam War. He was a lieutenant commander when an aircraft carrier he was serving on, the USS Forrestal, caught fire and killed 134 sailors. He was able to escape and volunteered for another assignment on another aircraft carrier, which was used in Operation Rolling Thunder.
3. He refused early release from a POW camp in Hanoi
McCain's capture and torture at the hands of the North Vietnamese is also well known. When his captors found out that McCain's father would be commander of all the U.S. forces in the region, they offered to release him. McCain refused to be released unless everyone else taken with him was also released. In total, he spent five and half years as a prisoner of war. Two of those years were spent in solitary confinement.
4. He adopted an orphan from Bangladesh
Cindy McCain, who became a household name during McCain's political campaigns, was his second wife. In 1991, she brought a three-month-old Bangladeshi girl to the U.S. for medical treatment. The McCains adopted her and named her Bridget.
5. The nickname 'Maverick' came from his willingness to disagree with his party
McCain had to retire from military service mainly due to injuries he had sustained as a POW. He had also made plans to get involved in political life. With his growing family, he settled in Arizona and ran for a congressional seat from there. Though he initially had Republican views aligned with those of Reagan, he also developed a reputation for disagreeing with his party. As a senator, he voted to confirm President Clinton's Supreme Court nominees, Stephen Breyer and Ruth Bader Ginsburg; he opposed war in Somalia; he took on the tobacco industry by trying to raise cigarette taxes.
6. He ran for president twice, and lost both times
McCain first ran for president in 2000, but didn't make it past the primary, which he lost to George W. Bush. After his loss, he returned to the Senate for his third and fourth term. In 2008, he ran for president again, and this time won the Republican nomination. Choosing Sarah Palin as his running mate ended up being a poor decision, and Barack Obama won decisively against him. However, he is remembered for defending Obama against racist accusations made by some Republican voters during his campaign. He continued serving as a senator from Arizona.
7. He planned for his funeral to be a criticism against the current administration
McCain put a mark on himself when he withdrew support for Trump's presidential bid after his offensive comments on the campaign trail. In retaliation, Trump had some unpleasant tweets for McCain, and has repeatedly denigrated him for getting captured in Vietnam. McCain had been critical of his presidency, and purposely designed his funeral to be a rebuke. He has asked Bush and Obama to deliver a eulogy for him. Though McCain was not close to Obama personally, it is meant to be a mark of mutual respect. McCain had also made it clear that he did not want Trump or his 2008 running mate Palin to attend the funeral.