Washington - Hillary Clinton is stepping down as the top US diplomat firm in the belief she has restored America's global standing during her tenure that may also have traced a path to the White House in 2016.
But as she sweeps out of the imposing buildings of the State Department for the last time on Friday, how will history judge her as secretary of state?
How she stacks up against giants of American diplomacy like Henry Kissinger and James Baker and how she'll fill in the blank pages as she opens a new chapter in her life remain open questions.
Clinton says she never once gave a thought to her legacy in the past four years. Instead, she just got up every day determined to work as hard as she could to promote America's interests.
She now leaves office with the highest popularity rating of any of President Barack Obama's cabinet members, imbued with the title of "rock star diplomat" and with many saying she'll be the Democratic Party's strongest hope in the next elections, despite her constant denials that she is planning to run.
"Her contribution I think was fighting for resources for her own department, America's credibility in the world through her relentless travel, finding a 21st century agenda, I call it planetary humanism," said Wilson Centre vice president Aaron David Miller.
"These are important issues. They don't get you into the secretary of state hall of fame," Miller, a distinguished scholar who has served under six secretaries of state, said.
Critics say Clinton cannot point to a signature issue achieved under her stewardship. The major challenges of the day - Syria, the new world order emerging from the Arab Spring, Iran's nuclear ambitions and the search for peace in the Middle East - she bequeaths to her successor John Kerry.
Yet the Obama administration seized the opportunity to help prise open Myanmar, she showed effective diplomacy in negotiating the freedom of Chinese dissident Chen Guangcheng, helped the United States pivot its focus toward Asia and built a solid alliance in support of biting sanctions against Iran.
And Clinton brought to Obama's administration her charisma, celebrity status and a willingness to travel, believing that even in this interconnected world, face-to-face meetings remain one of diplomacy's most important tools.
"Secretary Clinton, because of her celebrity and popularity, has been a great secretary of state from that respect. People are thrilled to meet with her. She's probably second best to meeting with Obama," said Isobel Coleman, senior fellow at the Council on Foreign Relations.
Even hardened politicians found it hard to resist her charms, British Foreign Secretary William Hague revealed during a dinner in her honour.
"There is a wonderful stillness that descends on large halls full of diplomats and ministers the moment Hillary enters the room," he said.
Hague praised Clinton's "infectious spirit of optimism, opportunity and hope" as well as her faith "in the power of friendship and persuasion".
In pursuit of diplomacy, Clinton has travelled exactly 1 539 712.5km, visiting about 112 countries. She was the first US secretary of state ever to visit Togo, and the first in over half a century to fly into Laos.
"Remember what we faced in January 2009: Two wars. An economy in freefall. Traditional alliances fraying. Our diplomatic standing damaged," she told the Council on Foreign Relations on Thursday.
"And around the world, people questioning America's commitment to core values and our ability to maintain our global leadership.
Much has changed
"That was my inbox on day one as secretary of state."
Four years on, while the world "remains a dangerous and complicated place", much has changed, Clinton argued, saying "we've revitalised American diplomacy and strengthened our alliances".
Those dangers were highlighted by the September attack on the US mission in Benghazi, Libya, in which the ambassador Chris Stevens and three other Americans were killed.
Whether the attack, and the scathing criticism of security failures by the State Department, will taint her career in the long-term is too soon to tell.
Many argue that Clinton's emphasis on what she calls "soft power" - her unrelenting focus on women's rights, development issues, economic statecraft and lesbian and gay rights - may well be what she's remembered for.
"As a long-term enduring legacy, I think I'd feel prouder about that than having invaded another Middle Eastern country," Coleman said.
Observers also point to Europe's renewed faith in America, after Clinton made 42 trips to the continent during her time in office.
"In 2009, everything needed to be rebuilt... she has succeeded in restoring America's image in the world. She has marked the return of multilateralism," a western diplomat said in an interview.
Tyson Barker, director of transatlantic relations at the Bertelsmann Foundation North America, agreed that "Europe loves Hillary Clinton, and she's spent a lot of time here investing in that relationship.
"She has really carried the torch for reconciliation and European integration."