WASHINGTON, DC, USA (AFP) — Forget about deja vu or old hat as Barack Obama, America's first black president, was sworn in again. For some in the sea of humanity watching, cheering and shivering, the repeat was even sweeter.

Yes, the crowd was smaller and the number of celebratory balls was slashed. Obama will be a lame duck, barred from seeking a third term. Compared to 2009, even the January cold that tested the mettle of Obama fans was less intense.

Still, for the crowd that roared when Obama stepped onto the VIP podium on the steps of Congress, one message was clear: his first win back in 2008 was not just some fleeting blip or anomaly amid a long stream of white presidents.

"I am very excited. I feel like the second time around is better," said Jessica Austin of Tuscaloosa, Alabama, who travelled to Washington for the inauguration.

"It is worth even more, that he did it again," said Austin, an African-American, like a clear majority of the crowd thronging the National Mall.

Indeed, said 25-year-old Washington law student Max Etin, who is white, this time may be less frenzied in terms of enthusiasm but the deeper significance of Obama's win last November speaks volumes.

"I think it is still exciting for some people to show it wasn't like a fluke, you know? That really America is behind him and America is a changing country and he kind of embodies that," said Etin.

A festive atmosphere engulfed the city, one often given to snotty political bickering but owned utterly for a day by the Obama buzz.

From the steps of the Capitol, atop which the majestic white dome stood out against the gray, low-hanging sky, a speckled and colourful carpet of hundreds of thousands spilled out along the huge green lawn known as the Mall.

Nearby, a lone saxophone player played Dave Brubeck music.

Picnics were eaten. Boy scouts squatted on the grass to munch on box lunches. One woman, wrapped in a red plaid blanket and leaning against a tree, hugged a bump that concealed a future child.

After the inauguration, Obama had lunch in the Capitol with congressional leaders and took a slow ride down Pennsylvania Avenue, home to the White House, on his way to view the official inaugural parade from glass-encased VIP stands.

At two points along the way, Obama and his wife Michelle got out of the Cadillac presidential limo and strolled, at times hand in hand, smiling broadly and waving to the crowd on either side of the broad avenue.

The first lady wore a high-waisted flared blue coat. The crowd yelled enthusiastically at the presidential couple. Some had been waiting for the moment up to six hours.

Inaugural officials estimated the crowd — from the Capitol stretching down the Mall and along Pennsylvania Avenue — at one million people.

The parade itself featured eight official floats and 60 groups including marching bands, mounted units and military people.

During the Obama motorcade, part in the run-up to the parade itself, the crowd screamed its delight as Washington police rode by on Harley-Davidsons with sidecars and revved their mighty engines.

Back at Capitol Hill, people watched large screen TVs showing the arrival of politicians to the VIP podium on high, cheering ones they liked and booing some others.

Etching their taste of history in digital memory, people posed for photos holding their admission ticket — green, yellow or orange depending on where they were assigned to stand — with the Capitol as the backdrop.

The wardrobe protecting against the damp cold was as varied as the crowd, from full-length fur coats to clusters of college students wearing bright yellow inaugural hoodies to goofy panda-head hats.

At one point, as a motorcade sped by on its way up Capitol Hill, people whooped, believing it was Obama, the man himself. Nobody knew for sure.

Still, one lady shouted out, and drew laughter: "There he is, there is my baby."

Justin Mausel, a 35-year-old government employee, agreed the electricity that was in the air four years ago wasn't there this time, or at least not as patently crackling.

Nevertheless, this was huge stuff: America's first black president, re-elected, wiping away any question of legitimacy.

"I think it is just as historic," said Mausel, his 16-month son Mijan squirming in a harness on his chest. "It is still very exciting."

Austin, the Alabama advertising employee, said there was also a sort of bittersweet element, as if it were the start of a farewell. She and others wondered aloud when there might ever be another African-American president.

But at the same time, she said, it is a chance for Obama — his plate full with a sputtering economic recovery and looming international crises — to get things done, and better.

"It is the beginning of a goodbye, and hopefully we can do better the second time around. It is the second chance to start over."