Graham, who long suffered from cancer, pneumonia and other ailments, died at his home in North Carolina on Wednesday, spokesman Mark DeMoss told The Associated Press.

Graham built evangelicalism into a force that rivalled liberal Protestantism and Roman Catholicism in the United States.

His proselytising in more than 185 countries and territories forged powerful global links among conservative Christians, and threw a lifeline to believers in the communist-controlled Eastern bloc.

Dubbed America's pastor, he was a confidant to US presidents from Dwight Eisenhower to George W Bush.

In 1983, President Ronald Reagan gave Graham the Presidential Medal of Freedom, America's highest civilian honour.

Beyond Graham's public appearances, he reached untold millions through his pioneering use of prime-time telecasts, network radio, daily newspaper columns, evangelistic feature films and globe-girdling satellite TV.

Graham preached with a conviction that won over audiences worldwide.

"The Bible says," was his catch phrase, while his unquestioning belief turned the Gospel into a "rapier" in his hands, he said.

A tall, striking man with thick hair, stark blue eyes and a firm jaw, Graham was a commanding presence at his crusades.

By his final crusade in 2005 in New York City, he had preached in person to more than 210 million people worldwide.

No evangelist is expected to wield influence like him again again.

Born November 7, 1918, on his family's dairy farm near Charlotte, North Carolina, Graham came from a fundamentalist background that rejected other Christians on minor differences over Scripture.

Graham's path to becoming an evangelist began taking shape at age 16, when the Presbyterian-reared farm boy committed himself to Christ at a local tent revival.

After high school he went to a series of religious colleges, including one in Florida where he'd practise preaching in a swamp to the listening birds and alligators.

Graham, who became a Southern Baptist, settled on studying at a Christian liberal arts school in Illinois, where he met fellow student Ruth Bell, who he'd later marry in 1943.

He gained a national profile in 1949, when media descended on his canvas cathedral in Los Angeles after legendary publisher William Randolph Hearst ordered his papers to hype Graham. Graham said he never found out why.

Over the next decade his international tours made him a global religious superstar.

In the 1950s, he faced the scorn of fundamentalists as he embraced broader society and joined the emerging New Evangelicalism movement, an approach that helped establish and cement the religion's influence.

Graham never joined civil rights marches, but did end racially segregated seating at his Southern crusades in 1953, and refused to visit apartheid South Africa.

In a 2005 interview with The Associated Press, Graham said he regretted not fighting more for civil rights.

"I think I made a mistake when I didn't go to Selma" with many clergy who joined the historic Alabama march led by the Reverend Martin Luther King Jr.

Graham said he must preach to all, regardless of political affiliation, however in 2012 he all but endorsed Republican presidential nominee Mitt Romney.

His ministry also took out full-page ads in newspapers supporting a potential ban of same-sex marriage, which Graham saw as a moral not political issue.

Graham's relationship with President Richard Nixon caused him trouble during the Watergate scandal and again also threatened the preacher's reputation when tapes released in 2002 caught Graham telling the president Jews "don't know how I really feel about what they're doing to this country".

Graham apologised, saying he didn't recall ever having such feelings.

While scandals plagued other television evangelists, Graham resolved early on never to be alone with a woman other than his wife. He also never took money at his sermons, instead earning a modest salary from the Billy Graham Evangelistic Association.

He was on the road for months at a time, leaving wide Ruth at their mountainside home in Montreat, North Carolina, to raise their five children: Franklin, Virginia, Anne, Ruth and Nelson.

Ruth sometimes grew so lonely when Billy was travelling that she slept with his tweed jacket for comfort.

She died in June 2007 at age 87.

Graham will be buried by his wife, Ruth, at the Billy Graham Museum and Library.

"I have been asked, 'What is the secret?"' Graham had said of his preaching. "Is it showmanship, organisation or what? The secret of my work is God. I would be nothing without him."

Australian Associated Press