Americans are choosing between Hillary Clinton and Donald Trump as voting in the US presidential election goes into full swing.
It began with a handful of villages in New Hampshire just after midnight before states throughout the East Coast started polling at 06:00 EST (11:00 GMT).
Mrs Clinton cast her vote with Bill Clinton in Chappaqua, New York state.
She and Mr Trump both targeted battleground states on Monday.
A hectic round of campaigning took them both to rallies in North Carolina, Pennsylvania and Michigan.
Americans are choosing a new president after one of the most rancorous election campaigns the country has seen.
Democratic contender Mrs Clinton urged voters to back a “hopeful, inclusive, big-hearted America” while Mr Trump told supporters they had a “magnificent chance to beat the corrupt system”.
Polls give Mrs Clinton a four-point lead over Republican Mr Trump.
A record number of Americans – more than 46 million – have voted early by post or at polling stations.
There are signs of a high turnout among Hispanic voters, which is believed to favour Mrs Clinton.
Long queues have formed at polling stations in the key battleground state of Virginia, a BBC correspondent reports.
The rivals held the final rallies of their campaigns after midnight – Mr Trump in Grand Rapids, Michigan, and Mrs Clinton in Raleigh, North Carolina.
“Today the American working class is going to strike back, finally,” said Mr Trump, pledging to reverse job losses.
Media captionDonald Trump urged supporters in New Hampshire to “dream big”
Earlier, in New Hampshire, he told supporters: “We are just one day away from the change you’ve been waiting for all your life.
“Together we will make America wealthy again, we will make America strong again, we will make America safe again and we will make America great again.”
Mrs Clinton told her audience that they did not “have to accept a dark and divisive vision of America”.
She looked forward to “a fairer, stronger, better America. An America where we build bridges, not walls. And where we prove conclusively that love trumps hate”.
Election day follows a bitter campaign during which the candidates have traded insults and become mired in a series of scandals.
At a star-studded event in Philadelphia, Pennsylvania, Mrs Clinton was joined on stage by celebrities Bruce Springsteen and Jon Bon Jovi as well as her husband Bill, President Obama and his wife Michelle.
At his rally in Scranton in the same state, Mr Trump insisted the momentum was with his campaign.
The businessman described Mrs Clinton as the “most corrupt person ever to seek the presidency”, referring to an FBI investigation into Mrs Clinton’s use of a private email server while she was serving as secretary of state between 2009 and 2013.
On Sunday Mrs Clinton’s campaign received a boost when the FBI said newly discovered emails sent by an aide showed no evidence of criminality.
Election day voting began just after midnight in the small New Hampshire village of Dixville Notch, where seven votes were cast – four for Mrs Clinton, two for Mr Trump and one for the libertarian Gary Johnson.
All 50 states and Washington DC will vote across six different time zones.
Results are expected some time after 23:00 EST (04:00 GMT on Wednesday) once voting ends on the West Coast. State projections will not be available until polling ends – in most states between 19:00 EST (24:00 GMT) and 20:00 EST (01:00 GMT).
Americans are also voting for Congress. All of the House of Representatives – currently Republican controlled – is up for grabs, and a third of seats in the Senate, which is also in Republican hands.
