Even before his swearing in, President Barack Obama rewrote history again as he and First Lady Michelle Obama went to church.
Later, as the Obamas went to the White House, a gigantic crowd gathered, filling the National Mall.
People streamed in from across America.
Police officials called it the largest crowd to ever gather in Washington.
An estimated two-million people were on hand as America's 44th President took the oath of office.
In his inaugural address, President Obama cited two wars, the economy, and global warming.
"Today I say to you that the challenges we face are real. They are serious and they are many," Mr. Obama said. "They will not be met easily or in a short span of time. But know this, America, they will be met."
To U.S. enemies there was tough talk.
"Our spirit is stronger and cannot be broken; you cannot outlast us, and we will defeat you," he vowed.
To fellow Americans, tough love.
"Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America," President Obama said.
The upbeat congressional celebration lunch was marred when Senator Ted Kennedy, fighting brain cancer, suffered convulsions, but the inaugural parade was triumphant.
A huge throng remained out in the cold for the warm rush of seeing President Obama.
Security was tight, but that didn't stop the traditional walk.