The hat itself may have been a fluke, but the slogan had a deeper history with Trump.

He started using the phrase as far back as 2011. It took on new meaning for Trump, however, in the wake of Mitt Romney’s defeat in 2012. In both style and substance, Trump felt Romney failed to project a positive vision of American strength. Just six days after that election, Trump signed paperwork to trademark the phrase “Make America Great Again.”

“He was in that chair — that iconic chair he has in his office on the 26th floor of Trump Tower — and he looked up and he said, ‘My slogan is going to be Make American Great Again,'” Sam Nunberg, a former campaign aide who helped lay the groundwork for Trump’s run, told CNN. “He looked up at the ceiling with a smirk on his face, and he said, ‘And watch, everybody’s going to love it.’ He was right.”

Trump’s opponent, Hillary Clinton, criticized the slogan as harkening back to an abstract time in American history, calling it a “cruel fantasy.” The phrase has been used in the past by Presidents Ronald Reagan, George H.W. Bush and even Clinton’s husband, Bill Clinton.

But in the history books, the slogan will belong to Trump.