WASHINGTON -- Perhaps the day's tone was set by the man at the foot of the Capitol South Metro station.

On a ripping cold day, with crowds pressed beyond comprehension into subway cars that took them to the inauguration of Barack Obama, a disembarking passenger at the foot of the long escalator began to chant:

"O-bam-a. O-bam-a."

The crowd picked up on the chant. The station filled with it.

"O-bam-a. O-bam-a."

The man's words beat him to the top of the steps, taken over by a crowd that blended into more than 1 million strong who stood shoulder-to-shoulder, soul-to-soul along the National Mall, waiting for history to be made.

"I've never seen the city like this," said one passenger.

On a day without precedent, the 44th president of the United States was surrounded by an ocean of hope, a tide of optimism, amid a sea of troubles.

Yes, there was the half-hour wait to get into the subway stations. Yes, it was cold and confusing and a 10-minute walk became an hour-long slog. Yet the sense of purpose overcame confusion as uncountable citizens in ski parkas, fur coats, knit caps and mittens trod through 28 degrees of cold into the warmth of a new era.

This was Barack Obama's crowd.

"I ain't tired," one elderly black woman told companions as they trudged the miles down D.C.'s streets to get a vantage point. "I waited all my life to get here. I'm gonna walk some more if I have to."

Vendors took up positions on the same streets as armored personnel carriers. The vendors hawked T-shirts with the presidential seal; the military crews on the carriers directed pedestrians and dispensed directions. Handmade chocolates, organic curried chicken wraps, grilled Thai chicken and cappuccino vied for sales along with something called Honest Tea, which its seller, Matt O'Brien, 24, of Brooklyn Heights, N.Y., insisted was Mr. Obama's favorite beverage.

Mr. O'Brien had staked out his spot 24 hours earlier, and slept the night in his hybrid car.

"I needed to make sure no one would drive off with the car," he explained.

Some came with nothing to sell, save their vision of hope.

"I'm not getting any younger, so I thought it was time to participate in something historic," said Carol Hale, 69, who, with her husband James, traveled from Atlanta to see yesterday's events. The Hales are black, and they are still astonished that a thing that seemed impossible in their youth has passed in front of their eyes.

"I'm still mesmerized. It isn't anything I ever dreamed would happen. I'm here to enjoy and soak up as much of it as possible," Mr. Hale said.

With barricades throughout the city, streets blocked and a mass of jolly confusion from the steps of the Capitol to those of the Lincoln Memorial, citizens from across town and across the continent walked circuitous detours, shivered together and made a morning and afternoon of it.

"It was crowded and cold, but it didn't bother you because you were so into the moment," said Caryn Bell, who traveled from Chicago.

Dustin Adams drove for a week from Santa Cruz, Calif., to attend, and ended his journey with a 15-block detour, on foot, to reach the mall.

"Walking those 15 blocks with all those people, shoulder-to-shoulder with each other, was probably my favorite part," he said.

Linn Myers, a 40-year-old Washington artist and former Regent Square resident, was one of those straining for a look.

"We decided to come down here because we don't get very good television reception," she laughed. "Plus, when you listen to the radio you're always hearing, 'Oh, I want to be able to tell my grandchildren I was there,' and everyone wants to be able to do that. I want to say I was here."

A few blocks to the west of the Old Executive Office Building, the crowd was finally diverted toward the Mall. A group of 11th graders from Yonkers, N.Y., posed with some animal rights protesters dressed as bears and foxes, smirking for the camera. How did they feel?

"Proud! Special!" shouted one youth, who didn't give a name. "We've been waiting for this for 400 years!"

Near the Washington monument, where hundreds of portable toilets stood like sentinels, a giant video screen showed men in heavy coats being escorted to their seats at the Capitol. When the screens showed Michelle Obama and Jill Biden emerging to be seated for the swearing-in, the crowd roared. A few minutes earlier, they had remained silent at the sight of Laura Bush and Lynne Cheney making their way to their seats.

Justin Jones, 8, and his 10-year-old brother, Jordan, of Orlando, Fla., waved their American flags and studied the screen. They would return home and give a PowerPoint presentation on their trip. They needed to make sure they remembered everything they saw. Their cousin, Madison Wright, 6, was just happy to be with them.

Why?

"Because I'm gonna see the president," she said with a grin, revealing two missing front teeth. It was a smile to warm a cold day.