As the first woman and the youngest person to be elected Alaska’s state governor, Sarah Palin is used to breaking new ground.
The 44-year-old was elected in 2006 and has been credited with bringing in reforms in her two years in office.
Presenting her as his running mate in November’s presidential election, John McCain described her as “someone with strong principles, a fighting spirit and deep compassion”.
As well as portraying her as a devoted wife and mother-of-five, Mr McCain also stressed her executive experience and ability to stand up against entrenched interests and corruption.
“She has the grit, integrity, good sense and fierce devotion to the common good that is exactly what we need in Washington today,” he said.
Mrs Palin is seen as boosting Mr McCain’s ticket because she is a woman – and so may appeal to disappointed Hillary Clinton supporters – as well as being young, energetic and from outside the Washington political scene.
She is also viewed as having a strong social and fiscal conservative record. She opposes abortion and holds a life membership of the National Rifle Association.
She is the first woman Republican to be put forward as a vice-presidential candidate. The only other woman picked as a running mate for a major party was Democrat Geraldine Ferraro, in 1984.
The governor – a former local beauty queen – is keen on hunting and fishing and reportedly enjoys eating moose hamburgers. Married for 20 years, she gave birth to her fifth child in April – a son who has Downs Syndrome.
Her oldest son joined the US Army on 11 September last year and and is to deploy to Iraq on the same date next month.
Speaking alongside Mr McCain, Mrs Palin presented her family and described herself as having been “just an average hockey mom in Alaska” before becoming involved in politics.
Her rapid rise to the vice-presidential nomination had been unexpected, she said, but her career had always been driven by her desire to “put the people first”.
As governor, she had signed ethics reforms, reached across the aisle to Democrats and independents and endeavoured to cut wasteful spending, she said, and was prepared to take political risks to do what was right.
Mrs Palin also painted herself as picking the torch for women carried before her by Geraldine Ferraro and Mrs Clinton, who spoke of having put 18m cracks in the glass ceiling by her historic run for the Democratic nomination.
Commenting that it was 88 years almost to the day since American women gained the right to vote, Mrs Palin said it was time for them to “shatter that glass ceiling once and for all”.
Ms Palin is also head of the Alaska National Guard which demonstrates, Mr McCain’s campaign said, that she “understands what it takes to lead our nation”.
Nonetheless, she had been seen as a long-shot for the vice-presidential role, with critics pointing to her lack of experience on the national or international stage.
She was in 1984 crowned the beauty queen of the town where she grew up, Wasilla. She also competed in the Miss Alaska contest.
The first-term governor describes herself as a political maverick.
To win election in Alaska, she beat the incumbent governor in the Republican primary and then defeated a former Democratic Alaskan governor in the general election.
A recent Wall Street Journal article said of her: “When Sarah Palin was elected governor as a Republican outsider in 2006, she didn’t just take on an incumbent from her own party. She took on Alaska’s Republican establishment.”
‘Nothing to hide’
Mrs Palin has a reputation for tackling corruption, having led an investigation into ethics violations by state Republicans while serving on the Alaska Oil and Gas Conservation Commission in 2003.
However, she is currently herself under investigation by state lawmakers over the dismissal of a state public safety commissioner.
She is alleged to have sacked him because he did not dismiss a state trooper involved in a contentious divorce and child custody battle from her younger sister.
The governor told US network CNBC she had “nothing to hide” in the matter.
Before being elected as governor, she served on the council of Wasilla City Council, a town outside Anchorage, and was its mayor from 1996 to 2002.
A 2004 census gave Wasilla City, where Mrs Palin grew up after moving from Idaho aged three months, a population of 7,738.
She graduated from the University of Idaho in 1987, having studied journalism and political science.
She made occasional appearances as a television sports broadcaster.