On a day many said was freighted with history, hope and a sober sense of realism, large crowds massed in Washington Monday to witness the second inauguration of President Obama.

Though smaller than the throngs that came when Obama took office four years ago, it still appeared to be one of the biggest gatherings in history for a president’s second inauguration.

Portions of the Mall were standing room only, and latecomers were directed to an overflow area. Many left immediately after the inaugural speeches and were snared in Metro delays caused by crowding and equipment problems. But thousands of others lined Pennsylvania Avenue to watch the Obamas travel from the Capitol to the White House and review about 60 floats and bands.

Parade watchers chanted the president’s name as the afternoon motorcade glided past, and screamed in delight when he and the first lady alit from their limo and walked a spell. “Life changing, exciting, thrilling,” was how Ashley Williams, 17, of Cleveland, described the moment she saw the Obamas in person. “I was on the same street as him, breathing the same air.”

For others, it was a time for reflection. Many who attended mentioned the convergence of the ceremonial inauguration and Martin Luther King Jr. Day, saying that each lended more meaning to the other. That was particularly so for those old enough to have lived through segregation and the civil rights movement.

“I was in Memphis when Dr. King was assassinated and in Jackson State when Medgar Evers died,” said Earline Matthews, 80, a retired schoolteacher from Memphis who rode to the District in one of two bus loads of people from Tennessee. “I am just inspired for the future of America and that we can witness history.”

Yolanda Davis brought her 5-year-old daughter, Anastacia, from Ohio, saying it would help her child understand how much brighter her future looks because of King and Obama.

Davis said her grandparents grew up in the segregated South. Obama’s presidency underscores the progress the country has made, she said. “It shows we have come full circle in the way that we have been treated.”

A predominantly African American crowd gathered in front of the Smithsonian castle, cheering and waving flags.

Sandra and Ronnie Robinson of Birmingham, Ala., set up folding chairs to watch the inaugural ceremony. Ronnie Robinson, 54, said he was in first grade when the 16th Street Baptist Church in Birmingham was bombed by white supremacists. Four little girls were killed.

Attending Obama’s inauguration on the King holiday, he said, “is the culmination to the dream. If we’re ever going to get close to the dream, this is as close as we’re going to get.”

Like the Robinsons, Katherine Ward, a Naval officer, was attending an inauguration for the first time. Ward, who is African American, said she was serving in Iraq when Obama entered office. “Now I’m here to cheer him on,” she said. “Everything Martin Luther King marched for and spoke on has come true.”

Some snafus revolved around Metrorail. Several downtown stations were temporarily closed after signal problems and a disabled train between the Foggy Bottom and Rosslyn stations caused delays of up to 20 minutes on the Red, Blue and Orange lines.

Overcrowding played a role, too. As of 4 p.m., Metro reported about 538,000 rides had been taken. By the same time in the 2009 event, about 807,000 riders had entered the system.

Despite a rush-hour tempo of trains, long lines formed at several downtown Metro stations at L’Enfant Plaza, Federal Center SW, Metro Center and Foggy Bottom. Metro urged customers traveling to Blue Line stations in Virginia to use the Yellow Line as an alternate.

Nevertheless, the inaugural ceremony went much more smoothly than it did in 2009, when hundreds of ticket holders were trapped in the Third Street tunnel — the so-called Purple Tunnel of Doom — and missed the entire event.

This time, only a few people skipped the inauguration due to the massive crowds. Several would-be attendees left what was designated as the green ticket area, near Second and C streets SW.

Others were disappointed after being steered to an overflow area beyond the Washington Monument when the National Park Service declared portions of the Mall full.

But during the heart of the ceremony, a giant video screen near the monument malfunctioned, causing some to leave in frustration.

“It’s pointless to be here,” said one woman as she pushed her way through the crowd, headed away from the faltering screen.

Security was tight everywhere, and that contributed to long lines. Even after the parade had started at about 3:20 p.m., hundreds of people were still waiting to get through security lines at 14th Street and Pennsylvania Avenue. Some said it took up to two hours to maneuver their way into the viewing area.

The comparison with four years ago was on the minds of many people, who showed up from around the country and abroad. Some people who attended both inaugurations sounded wistful, missing the marvel and joy that were so much in abundance when the nation’s first black president took office in 2009.

“Last time, it was buoyant and jubilant and hopeful,” said Mike Savonis, 58, of Takoma Park, as he headed down Constitution Avenue with his daughter, Sarah, 14. “This time, there’s more reality. He has the Republican House to deal with, and the Congress generally, and the NRA.”

Citing gun control, climate change, immigration reform and Afghanistan, Savonis added, “I think there’s a sense that we have a lot of work to do.”

As at all inaugurations, there was a festive air to the day, with blue skies and temperatures above freezing. Merchants hawked Obama earrings and hand warmers. Hundreds of Boy Scouts and Girl Scouts fanned across the Pennsylvania Avenue parade route in red volunteer vests, helping paradegoers make it through the day.

Strangers along Pennsylvania Avenue talked about the meaning of the day, and sometimes the talk turned to race.

“This is a great moment for all black Americans,” said Ken Sloan, 54, a cook from Washington, who is black.

Ann Freeman, 56, a human resources worker from Washington, who was standing next to Sloan, said she hopes Obama in his second term will help reconcile ideological divisions.

There were reminders of political battles along the parade route and in the vicinity of the Mall. Small protests were held, by demonstrators from the left and the right.

On Pennsylvania Avenue, about eight people from the Westboro Baptist Church in Kansas protested abortion and gay rights. One anti-abortion protester climbed into a tree near the Capitol Reflecting Pool and refused to come down for several hours.

Anti-war protesters, meanwhile, decried the Obama administration’s defense policies.

Such is the grandeur of a presidential inauguration that many people who waited hours to be a part of it all were not even eligible to vote. That includes foreign tourists, workers and migrants.

Riyaz Sayed, 41, a human resources manager from India, said it had been his “lifetime dream” to witness an American president take office. “He is the most powerful person on Earth,” Sayed said, “and people all over the world who have never met him, even my parents back in India, have such hope in him.”