WASHINGTON (Reuters) - Democratic US presidential nominee Hillary Clinton and Republican rival Donald Trump face off on Monday in the first of a series of televised debates that could prove crucial to who wins the White House on Nov 8.
The first debate will take place at Hofstra University on New York state's Long Island. The Commission on Presidential Debates has scheduled two more such presidential matchups and a vice presidential debate in October.
The rhetorical contests, which first appeared on television in 1960, have provided some of the most memorable moments and quotations in modern American political history. Here is a look at the highlights over more than five decades.
1960: Richard Nixon v John F. Kennedy
Seventy million viewers watched the first televised American presidential debate, which pitted Republican Vice-President Richard Nixon against Democratic nominee John F. Kennedy.
Nixon was recovering from a hospital visit and had a 5-o'clock shadow, having refused makeup. In contrast, Kennedy's delivery was smooth and charismatic. Viewers focused on what they saw, not what they heard. Kennedy won the election.
1976: Gerald Ford v Jimmy Carter
In the first TV debate in 16 years, Democrat Jimmy Carter faced off against unelected incumbent President Gerald Ford.
This was also the first time vice-presidential candidates debated on television, with Republican US Senator Bob Dole squaring off against Democratic US Senator Walter Mondale. Carter benefited when Ford said: "There is no Soviet domination of Eastern Europe, and there never will be under a Ford administration." News media played up Ford's remark as a major blunder, and many analysts thought it helped Carter win the election.
1980: Jimmy Carter v Ronald Reagan
Carter appeared only in a second debate with Republican Ronald Reagan after boycotting the first one because it included a third-party candidate, John Anderson.
The president accused Reagan of planning to cut Medicare healthcare funding for the elderly. Reagan, who had complained Carter was misrepresenting his stands on any number of issues, said: "There you go again," and chuckled, prompting audience laughter and coining a catchphrase. Reagan won the election.
The encounter attracted 80.6 million viewers, the highest number ever for a presidential debate, according to ratings company Nielsen.
1984: Ronald Reagan v Walter Mondale
Reagan, 73, successfully defused the issue of his age during the second debate with Democratic candidate Walter Mondale, 56, when he quipped: "I want you to know that also I will not make age an issue of this campaign. I am not going to exploit, for political purposes, my opponent's youth and inexperience." Reagan was re-elected.
1988: George H. W. Bush v Michael Dukakis
The second presidential debate involving Republican Vice-President George H.W. Bush and Democratic challenger Michael Dukakis opened with a question to the Massachusetts governor on whether he would favor the death penalty for someone who raped and murdered his wife. The question was posed to bring out the human side of a candidate dubbed "the Ice Man." His laborious response on an emotional issue did just the opposite. Bush won the election.
The vice-presidential debate came alive when US Senator Dan Quayle, Bush's running mate, compared himself politically to John F. Kennedy. Democratic US Senator Lloyd Bentsen replied in quiet, deadly tones: "Senator, I served with Jack Kennedy. I knew Jack Kennedy. Jack Kennedy was a friend of mine. Senator, you're no Jack Kennedy."
1992: George H. W. Bush v Bill Clinton v Ross Perot
This year's three debates became the first time three candidates - Bush, Democrat Bill Clinton, and independent Ross Perot - shared the platform. Clinton won the election.
1996: Bill Clinton v Bob Dole
In the second debate between Republican Bob Dole and Clinton, Dole was asked by a student whether at 73 he was too old to understand the needs of young people. He replied that at his age, intelligence and experience meant he had the advantage of wisdom.
Clinton retorted: "I can only tell you that I don't think Senator Dole is too old to be president. It's the age of his ideas that I question." Clinton was re-elected.
2000: Al Gore v George W. Bush
Vice-President Al Gore and Republican contender George W. Bush took part in three debates. "We all make mistakes. I've been known to mangle a syllable or two myself," Bush said during the second of the debates, purposely mispronouncing the word"syllable."
During the first encounter, Gore drew negative reviews for sighing loudly while Bush spoke. The Texas governor and son of George H. W. Bush won the election.
2004: George W. Bush v John Kerry
The last debate between Bush and Democratic US Senator John Kerry offered voters a stark contrast in styles, with Bush sticking to simple arguments while Kerry released an array of facts to make his case. Bush was re-elected.
2008: Barack Obama v John McCain
The three Obama-John McCain encounters averaged 57.4 million viewers, more than the average for the three debates in 2004, according to Nielsen. Republican US Senator McCain, his back against the wall, turned in his best performance in the last debate, but Democratic US Senator Barack Obama won the White House.
The vice-presidential debate riveted about 69.9 million Americans, and thus tied as the second most-viewed debate ever.
Republican Alaska Governor Sarah Palin and Democratic US Senator Joe Biden clashed on the economy and Iraq during a lively but polite debate. She frequently displayed a folksy style. At one point, she said: "Aw, say it ain't so, Joe,"adding a "doggone it" for good measure.
Biden and Palin both said they would work to change current US economic policy to make it more friendly to middle-class workers, but Biden said that McCain had called the fundamentals of the economy strong as the financial crisis broke out.
2012: Barack Obama v Mitt Romney
Obama stumbled in his first debate with Republican challenger Mitt Romney, surprising and worrying his supporters. But in the second debate, Romney, responding to a question about gender pay equality, said he had "binders full of women" as candidates for Cabinet posts. The phrase became a meme on social media, with tweets, original artwork and a Facebook group spoofing the former Massachusetts governor.