CHICAGO — President Barack Obama won re-election tonight shortly after news outlets projected that he would claim electoral victory in battleground state Ohio.

“We’re all in this together,” Obama tweeted moments after NBC News announced the expected outcome. “That’s how we campaigned, and that’s who we are. Thank you.”

Former Massachusetts Gov. Mitt Romney called Obama to concede the presidential contest just before midnight, according to the Associated Press.

“This is a time of great challenges for America, and I pray that the president be successful in guiding our nation,” Romney told supporters gathered in Boston just before midnight.

At about 10:15 p.m., thousands of Obama supporters at McCormick Place began brimming with raucous applause as news channels called the presidential election for Obama.

The president left his home in Kenwood at about 9:30 p.m., according to a White House pool report. Obama then swung by the Fairmont hotel, where he had planned to address senior staff before heading to his campaign’s official watch party at McCormick Place.

In an email shortly after 11 p.m., Obama told supporters he could not have secured a second term without their dedication.

“I want you to know that this wasn’t fate, and it wasn’t an accident,” he wrote. “You made this happen.”

This story is being frequently updated to reflect new information about the president’s re-election. 

— Patrick Sviek