Hillary Clinton is officially running for president in 2016.
"Americans have fought their way back from tough economic times, but the deck is still stacked in favor of those at the top," Clinton said in a video message posted to her new campaign website on Sunday. "Everyday Americans need a champion and I want to be that champion."
In the video, which highlights the stories and images of a diverse group of Americans, Clinton said she is running "so you can do more than just get by -- you can get ahead and stay ahead."
"Because when families are strong, America is strong," she said. "So I'm hitting the road to earn your vote because it's your time. And I hope you'll join me on this journey."
The former secretary of state's announcement marks Clinton's second attempt to win the White House and become the first woman president of the United States.
According to the Clinton campaign, the next six to eight weeks will be a "ramp up" period. She plans to travel across the country, including a visit to Iowa this week, spending time "engaging directly with voters." The campaign said that she will hold a major kick-off rally sometime in May.
Clinton's daughter, Chelsea, congratulated her mother:
Before the video was released, an e-mail message sent to donors, supporters and elected officials by a top aide previewed the announcement.
"I wanted to make sure you heard it first from me -- it's official: Hillary's running for president," John Podesta, the chairman of Clinton's campaign, wrote in the message. "She is hitting the road to Iowa to start talking directly with voters. There will be a formal kickoff event next month, and we look forward to seeing you there."
In recent months, Clinton has worked behind-the-scenes to begin building a robust campaign apparatus, hiring a wide range of people, including many of President Obama's former advisers and strategists, for top positions in her campaign.
An office building in the Brooklyn borough of New York City will serve as the campaign headquarters. Clinton's staff gathered there on Saturday to talk campaign strategy and messaging.
A memo from Clinton's campaign manager, Robby Mook, and obtained by ABC News, outlined the campaign's guiding principles -- and offer a clear message: Unlike Clinton's 2008 campaign, this one aims to be drama free.
"We are open to a diverse range of views," Mook wrote. "When we disagree, it's never personal. Once a decision is made, we execute it -- together."
Allies and AdversariesClinton enters the race as the clear frontrunner for the Democratic presidential nomination. Over the past two years, pro-Democratic groups like Ready for Hillary and Emily's List have been working on her behalf to raise money, support and enthusiasm for her.
At this early stage in the campaign, Clinton also holds a clear lead over her potential Republican rivals. A recent ABC News-Washington Post poll showed Clinton ahead of potential GOP candidate Jeb Bush by a 54 to 40 percent margin in a potential match-up, with even bigger leads against Sen. Ted Cruz, Gov. Scott Walker, and Sen. Marco Rubio, who plans to announce on Monday whether he will launch his own White House bid.
Challenges AheadDespite Clinton's advantages, she has a challenging road ahead.
As a candidate, Clinton will also be expected to answer looming questions that have dogged her over the past few years, including her use of a personal e-mail account as secretary of state, the Clinton Foundation's acceptance of money from foreign governments, and her handling of the 2012 terrorist attack on the U.S. outpost in Benghazi, Libya.
Clinton has also suffered a significant drop in her favorability rating since leaving the State Department. The early April ABC News-Washington Post poll showed Clinton with a 49 percent favorability rating -- down nearly 20 points from her all-time high of 67 percent two years ago.
Family MattersAfter her defeat at the hands of Obama in 2008, Clinton repeatedly said "no" when asked whether she would ever seek the presidency again.
But in a newly-released epilogue to her memoir, "Hard Choices," Clinton, 67, indicated her new role as a grandmother may have influenced her decision to run.
"Rather than make me want to slow down," she wrote. "It has spurred me to speed up."