Obama, the Democratic candidate has won crucial state Ohio, according to AP. Earlier in the evening Obama also won Pennsylvania, another important state.
Battleground states still too early to call include Florida, Ohio, Virginia and Colorado, according to AP.
Obama was leading the electoral votes race by 175 to 61 against McCain. Obama needs 270 to clinch the presidency.
Although Obama was gaining ground in electoral votes, the popular vote was very close.
Obama had a 49.9 percent popular lead while McCain had 49.2 percent.