President Barack Obama made ​​history once again on Tuesday 6 November to make reelection in the United States in a very tight race against Republican Mitt Romney, according to projections by the television networks.

Obama became only the second Democratic president who won a second term of four years since the Second World War, after Bill Clinton.

Crowds around the country erupted into a cheer when the major television networks projected that Obama would win at least 274 electoral votes, more than needed to prevail on Mittr exgobernado Romney.

"This happened because of you. Thanks," Obama wrote to his 22 million followers on his Twitter account, which was announced after his victory in most of the states considered key.

Obama, who made history in 2008 by becoming the first black president of the United States, which is achieved in milestone for the country with a slogan of change and hope, will have many challenges ahead in his second term, when the economy country still recovering slowly from the worst crisis in decades.

Romney was in Massachusetts, after a long and hard struggle for the presidency, which bore no fruit. The two rivals were very even in the popular vote.

Romney had received 45.2 million votes, 49%. Obama had 45 million, the same proportion, after counting 65% of the districts.

But Obama won in the electoral college votes, which define the presidential election.

Assured and 284 electoral votes, 14 more than the 270 needed to realize victory. Romney had 200.

And Obama's lead was insurmountable even before they got the results in other states considered critical, such as Florida, Virginia and Nevada.