ABC News' Charles Gibson spoke with Sen. Hillary Clinton as part of the "Who Is" series, which features one interview a week with a presidential candidate from now until December, with a focus on their private lives.
Hillary Diane Rodham was born Oct. 26, 1947, in Chicago. Her father, Hugh Ellsworth Rodham, owned a textile business and her mother Dorothy Emma Howell, was a homemaker.
Her parents made a home for Clinton and her younger brothers, Hugh and Tony, in a middle-class suburb called Park Ridge.
"[Park Ridge] was an all-white suburb. I lived three blocks from my elementary school, so I walked home for lunch every day," she said.
Clinton described herself as "a pretty ordinary kid" in a "safe, secure and predictable world." Her upbringing, she said, was a combination of "Father Knows Best," "Ozzie and Harriet" and "Leave It to Beaver."
The Rodham household was politically conservative but straddled both parties, with her father being a Republican and her mother, a Democrat. Clinton would later characterize her own nature as "a mind conservative and a heart liberal."
When Clinton was 14, she did an eighth-grade science project on space medicine and decided she wanted to be an astronaut.
"I wrote NASA and said, 'What do you have to do to become an astronaut?'" Clinton told Gibson. "That was my question. I wanted to prepare myself."
NASA's response left Clinton both surprised and crestfallen.
"They said, 'Be a man.' They said, 'We're not accepting girls.' And I was crushed. I couldn't believe it," Clinton recalled, "To have my government tell me that there was something I couldn't do because I was a girl was shocking to me."
Instead, Clinton began reaching for the political stars. At the age of 13, she helped canvass the south side of Chicago in the 1960 elections and later volunteered for Republican Barry Goldwater in the 1964 presidential election.
"My best friend and I became quote 'Goldwater Girls,' Clinton said. "We got to wear cowboy hats. We had a sash that said, you know, I voted AUH2O. I mean, it was really a lot of fun."
But it was more than fun that drove Clinton to the Republican camp.
"Medicare and Medicaid was a big part of [Goldwater's] platform, or the civil rights law -- maybe it's not such a bad idea, to kind of require that people treat each other in a civil way," Clinton said of her thinking and political leanings as a teenager.
In 1965, Clinton graduated from high school and headed off to Wellesley College, where her political views and self-perception would take a drastic turn.
Becoming a Wellesley Woman
At Wellesley, Clinton majored in political science -- in and out of the classroom.
Though her activities displayed an unending energy and dogged gumption, Clinton considered quitting school her freshman year because she felt "totally out of place" and intimidated by the other more cosmopolitan students and the large college setting.
The star student struggled in her classes. To her embarrassment, her French teacher announced in front of the entire class, "Mademoiselle, your talents lie elsewhere."
She called her parents to tell them she wanted to quit school. Rather than coddle her, her mother responded, "Don't you dare," and both parents urged her to stay through the end of the year.
"And then I figured, well, since I have to stay for a year, I'd better throw myself into it," Clinton said.
During her first year of college, she became president of the Wellesley Young Republicans, though she later stepped down because of her views on the U.S. civil rights movement and the Vietnam War.
"I got to college and, by the time I really started thinking hard about what I thought about a lot of issues, I realized I might not know what I was, but I couldn't claim to be a Republican," Clinton said.
After the death of Martin Luther King in 1968, Clinton threw her support behind Democrat Eugene McCarthy's anti-war campaign. She collaborated with Wellesley's black students to call for changes, such as recruiting more black students and faculty to the school.
She graduated with honors in political science and became the first Wellesley student to give a commencement speech at graduation.
She then headed off to travel and work her way across Alaska, washing dishes at Mount McKinley and sliming salmon at a fish-processing cannery in Valdez. Clinton would later quip on the David Letterman show that sliming fish was the best preparation she ever had for working in Washington.
A Student of Letters
As demonstrated in her rousing speeches, Clinton is an impressive writer of letters, and the resulting paper trail has come back to haunt her more than once.
In July 2008, The New York Times published letters between Clinton and John Peavoy, a quiet Princeton-bound boy who attended high school with her in Park Ridge. Peavoy remained Clinton's prolific penpal throughout her college years.
The 30 or so letter exchanges document an introspective young woman experimenting with different identities -- a rare glimpse of a candidate known for her unfaltering confidence of character.
"Since Xmas vacation, I've gone through three and a half metamorphoses and am beginning to feel as though there is a smorgasbord of personalities spread before me, Clinton wrote in April 1967, "So far, I've used alienated academic, involved pseudohippie, educational and social reformer and one-half of withdrawn simplicity."
Embedded in the published letters was also an admission of insecurity and ambition, as she wrote that she was "not yet reconciled [herself] to the fate of not being the star."
Clinton recently admitted to a student group at a campaign event at Wellesley College that her commencement speech at her 1969 graduation "wasn't the world's most coherent address." At the time, she spoke passionately about student protests as "unabashedly an attempt to forge an identity in this particular age" and wanting a more "penetrating mode of living."
"I sort of cringe when I read that I actually said things like 'coming to terms with our humanness and authentic reality,' Clinton said recently to the delighted students. "Wellesley gets into you!"
But both speeches at Wellesley -- in 1969 and 2007 -- received an outpouring of wild cheers and clapping.
The commencement speech was also featured in Life magazine, casting Clinton as part of an upcoming generation of strong, outspoken women who took political change personally.
Bill and the Yale Years
After a professor at Harvard Law School insulted Clinton by telling her they didn't need more women, Clinton decided to attend Yale Law School, where women comprised 12 percent of her incoming class.
In the stacks of the law library in the fall of 1970, she noticed Bill Clinton looking in her direction and approached him with her characteristic boldness.
Clinton described one of her first encounters with Bill Clinton in her autobiography.
Marching up to him in the library, she said, "If you're going to keep looking at me, and I'm going to keep looking back, we might as well be introduced. I'm Hillary Rodham."
She wrote that Bill was "looking more like a Viking than a Rhodes scholar" when she first met him in 1970.
But only in the spring of 1971 did the Viking from Arkansas become more of a knight. After hearing her cough on the phone, Bill showed up at her door, armed with chicken soup and orange juice.
Clinton said in her book that she and Bill "became inseparable" from that moment on, taking long rides in Bill's orange Opel station wagon, which Clinton said was "truly one of the ugliest cars ever manufactured."
Back to Arkansas with Bill
After graduating from law school, Clinton wavered on whether to follow Bill to Arkansas. Her mind was made up for her when she failed the bar exam in Washington, D.C., but passed the Arkansas bar exam.
Despite their passionate and intellectual partnership, Clinton told Gibson that she was initially reluctant to marry Bill because he was a "force of nature" and "the center of most of the attention."
But Clinton said that her long-distance relationship with Bill after she graduated from law school was both emotionally difficult and costly.
"At every stage along my life, there have often come moments when I just had to -- in my view -- be as brave as I could be to try something that I needed to try, whether it was gonna work or not. And so, off I went to Arkansas," she explained.
By 1975, Clinton made up her mind.
"I told Bill, 'Let's get married next week.'" Bill Clinton and Hillary Rodham were wed in their living room the next week.
Being a First Lady
In 1992, when Bill Clinton won the presidency, he joked in a campaign speech that his election would give voters "Two for the price of one."
As first lady, Clinton perused his speeches, sat in on meetings and consulted his advisers on policy issues.
In "Living History," Clinton referred to 1998 as a low point, marked by the Lewinsky affair and Bill's impeachment by the House of Representatives. Though the Clintons managed to save Bill's presidency, Clinton described that period as a lonely time because she "did not want to talk to Bill as [she] had always done before."
Clinton later wrote in her autobiography that one of "the most difficult decisions I have made in my life was to stay married to Bill."
The Other 'Difficult Decision'
The other most difficult decision in Clinton's life was the one to run for the Senate from New York, Clinton said in "Living History."
The Clintons moved into a home in Chappaqua, N.Y., after leaving the White House.
But then in another chain of events as random as those which led her to Yale, Bill , and life in Arkansas, New York Sen. Daniel Patrick Moynihan announced he would not run for a fifth term in Senate.
A race that initially featured front-runners Clinton and New York Mayor Rudy Giuliani whittled down even further when Giuliani dropped out of the race, announcing he'd been diagnosed with prostate cancer. Clinton beat Rep. Rick Lazio by a 12 percent margin.
The murmurs of a possible presidential bid began as the first lady started to take her own place in the political spotlight, though Clinton denies having thought she'd like to be President until this past year.
"You know, some days -- let's just be honest -- it's scary, the idea of waging this campaign, getting out there, engendering all of the feelings -- pro and con -- that you do, because I'm neither as good, nor as bad, as my supporters and detractors probably think."
"Some days, it's such an enormous undertaking and adventure that it's exhilarating beyond words. You can't even imagine that it's you doing this," Clinton told Gibson. "Most days, it's, you know, pretty humbling and daunting at the same time."