With "Well hello, Iowa, I'm back," she began her speech Sunday at the 37th edition of the "Harkin Steak Fry", a fundraising barbeque organised by the Democratic senator from Iowa Tom Harkin, who is set to retire after 40 years in politics.
It was Clinton's first visit to Iowa since her defeat in the 2008 caucus by the then senator Barack Obama as a Democratic Party candidate for the presidential elections, to which she made a reference in her speech as well.
Referring to Obama, the former secretary joked, saying that the last time she was at the Harkin Steak Fry, she met a senator from Illinois, and wondered, "What will happen to him?"
"We went from being rivals, to colleagues, to friends," Clinton said, adding that she was surprised at Obama's decision to nominate her as the nation's top diplomat.
Winking at the audience - and to nearly 200 journalists accredited for the event in the face of a possible announcement - Clinton said that when they invited her to speak she was not sure how she was going to do it.
"I've got a few things on my mind these days," she said.
She referred to her future grandchild as her daughter Chelsea is due to give birth to her first child in a few weeks, before referring to "the other thing" in the midst of great applause.
"It is true I am thinking about it. But that's not why I'm here today," Clinton said, thanking Harkin for his political service and expressing her support for the Democratic candidates in November's mid-term elections.
Iowa is an agricultural state in the Mid West and is considered a "key" state since it votes first in the primaries and according to the analysts, the first results can shape the pattern of the rest of the elections.
Clinton was accompanied by her husband, former US president Bill Clinton.
While Clinton's participation was presented as a way of thanking Harkin for his decades of service, political analysts saw it as a wake-up call to set the tone for the election campaign.
"This is just one more step towards the formal presidential campaign," said the Washington Post.
"It is an opportunity for the Clintons to start exorcising the ghosts of their defeat in 2008," said the conservative Fox News channel.
Her return to public life began this summer with her book tour for "Hard Choices", which tells of her years as the head of American diplomacy.
At present she has her own support group, "Ready for Hillary", which in April raised $5.75 million and used the opportunity to promote her candidacy.
The group put pictures of Clinton at the airport's exit in Iowa's capital Des Moines, and put banners in the enclosure where they held the barbeque.
Half a dozen buses were hired to transport students from eight universities in Iowa to the barbeque in an effort to recruit organisers at the grassroots level and to bring the campaign closer to them.
One of the criticisms faced by Hillary at the beginning of her presidential candidacy in Iowa in 2008 was that she failed to convey the closeness that Obama managed to achieve.
The Harkin Steak Fry has become a high profile political event in a casual environment where potential candidates mobilise support at the grassroots level and also gather support among members of their party.
Former president Clinton has appeared on three occasions, in 1992, weeks before being elected president; in 1996 when he returned with then vice president Al Gore during the re-election campaign; and in 2003 prior to the 2004 presidential caucuses.
Obama appeared at the Harkin barbecue in 2006 when he began to gain popularity as a senator and a year later he was among the six presidential candidates.