Conspicuously absent will be President Donald Trump, who over the past three years engaged in a public feud with McCain, a fellow Republican.
He pointedly did not invite President Trump, who had repeatedly mocked and belittled the respected GOP senator, first saying he wasn't a war hero because he was captured and later attacking him for not voting to repeal Obamacare. Following that, bipartisan leaders - McConnell and Senate Minority Leader Chuck Schumer and Ryan and House Democratic leader Nancy Pelosi - will present wreaths.
The Arizona Cardinals superstar - who grew close to McCain since he joined the National Football League in 2004 - says it was an unlikely pairing. but that's what made it so special.
Longtime McCain friend Tommy Espinoza told the 3,500 mourners that "We all make America great", a similar phrase to Trump's campaign slogan, "Make America Great Again".
Just before 11.00 am Friday, a military honor guard solemnly carried the senator's flag-draped casket up the Capitol stairs, moving deliberately one slow step at a time.
A long line of people has stretched around the U.S. Capitol today.
Sen. John McCain will be honored at the National Cathedral in Washington, D.C., Saturday in a memorial that will include speeches from two former presidents.
Former political science professor Kevin O'Farrell said it's a reflection of both the decades of work McCain did in Congress and the life he lived.
A light rain that turned heavy fell as body bearers from various branches of the military began the solemn procession up the stairs of the Capitol to rest the casket on the stand where McCain will lie in state until Saturday morning. Several presidents, including Abraham Lincoln, have also lain in state and McCain's casket will lie atop Lincoln's catafalque, a wooden structure that has been used in several ceremonies in past years. Saturday will be headlined by eulogies by two former American presidents Barack Obama and George W. Bush. Lindsey Graham. While in the chamber, Cindy McCain sat in her husband's chair.
At a Capitol Rotunda ceremony, Republicans and Democrats called a temporary political truce to honour McCain on the third of five days of memorial celebrations in Arizona and Washington for the Vietnam War hero and two-time Republican presidential candidate.
McCain, who died last Saturday at age 81 after fighting brain cancer, was one of the leading United States political figures in the last few decades after being a prisoner of war in Vietnam and serving as a senator from Arizona for more than 30 years.
When asked whether the president missed a chance to unite a mourning country, Trump defended himself.
And he spoke directly to McCain's widow, Cindy McCain, in the front row: "You were his ballast".
For approximately seven minutes, Fitzgerald recalled McCain's accomplishments in life and devotion to his family, the state of Arizona and service to the people of the U.S. He will be buried on Sunday at the US Naval Academy in Annapolis, Maryland.
McCain relished his time in Congress, a place he had not returned to since December 2017 as he fought brain cancer.
McCain chose a Russian dissident as a pallbearer, though Trump has professed repeatedly his affinity and admiration for Russian President, Vladimir Putin - praise that came amid special counsel Robert Mueller's probe into Russian meddling in the 2016 presidential election.