“I’m running for president,” she said with a smile near the end of a two-minute video released just after 3 p.m.
“Everyday Americans need a champion. And I want to be that champion,” Mrs. Clinton 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 announcement came minutes after emails from John D. Podesta, Mrs. Clinton’s campaign chairman, alerting donors and longtime Clinton associates to her candidacy.
Mr. Podesta said that Mrs. Clinton would meet soon with voters in Iowa and host a formal kickoff event some time next month.
The announcement effectively began what could be one of the least contested races, without an incumbent, for the Democratic presidential nomination in recent history — a stark contrast to the 2008 primaries, when Mrs. Clinton, the early front-runner, ended up in a long and expensive battle won by Barack Obama. It could also be the first time a woman captures a major party’s nomination, The New York Times reported.
Regardless of the outcome, Mrs. Clinton’s 2016 campaign will open a new chapter in the extraordinary life of a public figure who has captivated and polarized the country since her husband, former President Bill Clinton, declared his intention to run for president in 1991. Mrs. Clinton was the co-star of the Clinton administration, the only first lady ever elected to the United States Senate and a globe-trotting diplomat who surprised her party by serving dutifully under the president who defeated her.