Washington: (Agencies: 3/11/2008): The US presidential rivals have spent a hectic final day of campaigning criss-crossing the country in a last push for votes in key states.
Republican John McCain, trailing in opinion polls, started early in Florida and was to finish in Arizona. He urged his supporters to fight on to victory.
Democrat Barack Obama, at his last campaign rally in Virginia, told voters he had one word for them: "Tomorrow."
Today voters will give their verdict and pick the 44th US president.
In a symbolic opening to election day on the US east coast, Mr Obama defeated his rival by 15 votes to six in the hamlet of Dixville Notch, New Hampshire.
Both camps are keenly aware of the need to get voters out in the states that polls suggest remain in the balance. Various polls suggest Mr Obama has a two- to four-point lead over McCain in electoral vote-rich Florida.
Both campaigns have thousands of volunteers working flat-out manning phone banks, handing out brochures and knocking on doors ahead of today’s election.
Some 130 million Americans are expected to vote, in a higher turnout than in any election since 1960, the BBC’s North America editor Justin Webb says.
A record 27 million people had already cast absentee or early ballots as of Saturday night.
Under America’s Electoral College system, states are apportioned votes based on their population, the biggest being California with 55 votes. A candidate needs to gain 270 out of the 538 Electoral College votes to win the presidency.
When Americans go to the polls, as well as choosing a new president and members of Congress, they will be casting votes on a wide range of ballot initiatives such as same-sex marriage, abortion and animal rights.
Polls suggest the six closest state races on election day will be in Florida, Indiana, Missouri, North Carolina, Nevada and Ohio. Mr McCain holds the lead in Indiana and North Carolina, but Mr Obama is ahead in the others, the latest polls from Reuters/C-SPAN/Zogby suggest.