Obama left the train briefly in Baltimore to address a frozen-but-hearty crowd of more than 40,000, echoing his earlier remarks and alluding to the men who defended nearby Fort McHenry.

More than a thousand mini-figures are shown on display as Legoland unveils a replica of the 56th presidential inauguration in Carlsbad, California January 16, 2009. [Agencies]

"We are here today not simply to pay tribute to those patriots who founded our nation in Philadelphia or defended it in Baltimore, but to take up the cause for which they gave so much," he said.

Back in Washington, members of his administration looked beyond the inauguration to the details of governing.

Obama adviser Valerie Jarrett addressed the US Conference of Mayors and asked for help pushing through legislation to jump-start the moribund economy.

Although Obama's path tracked Lincoln's and took on the same overtone of high security, it wasn't the journey of virtual secrecy that the 16th president-elect took so long ago on the eve of the Civil War. Lincoln was smuggled under cover of darkness from one train station to another to avoid a feared assassination attempt.

The FBI has been planning for the inauguration since June. Large trucks, a bomb-detecting robot, canisters with hundreds of gallons of water to disrupt a car bomb and other emergency response equipment stretch down a block near the FBI's Washington Field Office.

John Perren, a special agent in charge of counterterrorism, said there was no credible intelligence warning of any attack.

"We're very, very confident that if anything happens, we know how to respond to it," Perren said.