President-elect Barack Obama addresses his supporters

Democrat Barack Obama has been elected the first black president of the United States, as his Republican rival John McCain conceded defeat.

Latest electoral college projections: Obama 338: McCain 155

Obama has arrived on stage at Grant Park in Chicago and is delivering his acceptance speech.

He said: "Hello Chicago. If there is anyone out there who still doubts that all things are possible... who still questions the power of democracy, tonight is your answer."

"We are and always will be the United States of America."

Obama paid tribute to John McCain. "We are better off for the service rendered by this brave and selfless leader." He said he looked forward to working with McCain and Sarah Palin "to renew this nation's promise".

He added: "The road ahead will be long, the climb ahead will be steep.... but America I have never been more hopeful that we will get there. We as a people will get there," Obama said, while the crowd chanted: "Yes we can."

Celebrations are taking place across Chicago, outside the White House in Washington DC, and in Kenya.

In Phoenix, Arizona, John McCain delivered his concession speech. He said: "The American people have spoken and they have spoken clearly." The crowd booed when McCain said he had called Obama to congratulate him on winning the presidency.  McCain silenced the crowd.

"Senator Obama has achieved a great thing for himself and for his country. I applaud him for it."

McCain urged all Americans to find ways to come together, help restore prosperity and security and "leave our grandchildren a better country than we inherited." 

"It is natural tonight to feel some disappointment but tomorrow we must move beyond it and work together to get our country moving again... The failure is mine, not yours," McCain told the crowd.

We're continuing to track the election results as they come in. Add your own information on exit polls and voting results in the comments. You can also see latest results from the microblogosphere by using our Scan tool.

Full list of states reporting:

Alabama: McCain WIN. 9 votes
Alaska: 3 votes
Arizona: McCain WIN. 10 votes
Arkansas: McCain WIN. 6 votes
California: Obama WIN. 55 votes
Colorado: Obama WIN. 9 votes
Connecticut: Obama WIN. 7 votes
Delaware: Obama WIN. 3 votes

District of Columbia: Obama WIN. 3 votes

Florida: Obama WIN. 27 votes
Georgia: McCain WIN. 15 votes
Hawaii: 4 votes
Idaho: McCain WIN. 4 votes
Illinois: Obama WIN. 21 votes
Indiana: 11 votes
Iowa: Obama WIN. 7 votes
Kansas: McCain WIN. 6 votes
Kentucky: McCain WIN. 8 votes
Louisiana: McCain WIN. 9 votes
Maine: Obama WIN. 4 votes
Maryland: Obama WIN. 10 votes
Massachusetts: Obama WIN. 12 votes
Michigan: Obama WIN. 17 votes
Minnesota: Obama WIN. 10 votes
Mississippi: McCain WIN. 6 votes
Missouri: 11 votes
Montana: 3 votes
Nebraska: McCain WIN. 5 votes
Nevada: Obama WIN. 5 votes
New Hampshire: Obama WIN. 4 votes
New Jersey: Obama WIN. 15 votes
New Mexico: Obama WIN. 5 votes
New York: Obama WIN. 31 votes
North Carolina: 15 votes
North Dakota: McCain WIN. 3 votes
Ohio: Obama WIN. 20 votes
Oklahoma: McCain WIN. 7 votes
Oregon: Obama WIN. 7 votes
Pennsylvania: Obama WIN. 21 votes
Rhode Island: Obama WIN. 4 votes
South Carolina: McCain WIN. 8 votes
South Dakota: McCain WIN. 3 votes
Tennessee: McCain WIN. 11 votes
Texas: McCain WIN. 34 votes
Utah: McCain WIN. 5 votes
Vermont: Obama WIN. 3 votes
Virginia: Obama WIN. 13 votes
Washington: Obama WIN. 11 votes
West Virginia: McCain WIN. 5 votes
Wisconsin: Obama WIN. 10 votes
Wyoming: McCain WIN. 3 votes

The first polls closed on the US East Coast at 1800 EST and in some cases projections are expected as soon as voting ends. The last polls close in Sarah Palin's home state of Alaska at 0100 EST on Wednesday.