Visiting a campaign office in his hometown of Chicago, Obama thanked volunteers for their hard work on his campaign.  He then addressed his remarks to Governor Romney and to all Americans to exercise their power through the ballot box to determine the nation's future.

"To Governor Romney, congratulations on a spirited campaign," said Obama.  "I know that his supporters are just as engaged and just as enthusiastic and working just as hard today.  We feel confident we've got the votes to win, but it's going to depend ultimately on whether those votes turn out.  And so I would encourage everybody on all sides just to make sure that you exercise this precious right that we have that people fought so hard for us to have."

Obama completed formal campaigning on Monday.  Romney added stops in the important battleground states of Ohio and Pennsylvania, attempting to sway undecided voters his way.

In Cleveland, Ohio, Romney thanked his campaign workers and expressed confidence in his chances to win the White House.

"This is a great day with great opportunity ahead," said Romney.  "But I am also looking forward to tomorrow, the work that people were hoping they would see done from their nation's leaders.  Paul Ryan and I are going to do that; we're going to get America back on track."

Public opinion surveys show Obama and Romney in a virtual tie.  But President Obama holds a very slight advantage in several battleground states.

To win the presidency, a candidate needs to win at least 270 electoral votes that are distributed across the 50 U.S. states and the District of Columbia.

With election results perhaps only hours away, President Obama spent part of Tuesday playing basketball with friends, advisers and at least one member of his Cabinet, a tradition he established early in his political career.

Obama and first lady Michelle Obama will be joined by Vice President Joe Biden and Mrs. Biden for dinner at the Obamas' home in Chicago.

Later, the Obamas and Bidens are scheduled to go to Chicago's convention center for an election night watch party, waiting for the results to come in.