With President Barack Obama and Republican challenger Mitt Romney locked in an intense battle for the White House, American today voted in an election that followed one of the most expensive and negative campaigns, with pundits predicting a wafer-thin win for the incumbent.
Voters from a small township in the battleground New Hampshire State were the first to cast their ballot shortly after midnight when the polling began.
Dixville Notch in New Hampshire has been casting the first ballot of presidential elections since 1960. So far, it has picked seven out of 13 winners.
For the first time ever, the vote was tied in the township, with both Obama, 51, and Romney, 65, receiving five
votes each, another indication of the knife's edge separating the two candidates.
Unlike India and in most of the democracies across the world where the entire nation has one time for the opening and closing of polls, the election schedule in the United States, world's largest democracies, varies from State to State.
In US, the President is not chosen by the popular vote, but indirectly through the electoral college, in which states vote based on population, with a candidate needing 270 out of 538 electoral votes to win.
Hours ahead of the today's elections in which over 180 million people were eligible to vote, both the Romney and Obama campaigns, in their speeches and conference calls with reporters, claimed that enthusiasm was on their side.
Though polling centres in the US opened this morning to decide who will sit in the White House for the next four years, over one-third of the voters have already exercised their franchise using the provision of early voting.
According to latest figures complied by the US Election Project of the George Mason University, more than 30.5 million voters had already cast their ballots.
Obama, who cast his vote through early voting along with First Lady Michelle Obama, led from the front as he became the first US President to do so.