BOSTON -- Some ran to honor the dead and wounded. Others did it to prove something about their sport, the city or their country. And some were out to prove something to themselves.
With the names of the victims scrawled on their bodies or their race bibs, more than 32,000 people crossed the starting line Monday at the Boston Marathon in a powerful show of defiance a year after the deadly bombing.
"We're marathon runners. We know how to endure," said Dennis Murray, a 62-year-old health care administrator from Atlanta who finished just before the explosions last year and came back to run again. "When they try to take our freedom and our democracy, we come back stronger."
The two pressure-cooker bombs that went off near the end of the 26.2-mile course last year killed three people and wounded more than 260 in a hellish spectacle of torn limbs, smoke and broken glass.
The runners this time hit the streets under extraordinary security that included a battery of surveillance cameras, more than 90 bomb-sniffing dogs and officers posted on roofs.
By late afternoon, as runners continued to drag themselves across the finish line more than six hours into the race, state emergency officials reported no security threats, other than some unattended bags.
In what some saw as altogether fitting, Meb Keflezighi, a 38-year-old U.S. citizen who came to this country from Eritrea as a boy, became the first American in 31 years to win the men's race.
As he was presented with the trophy and laurel wreath, "The Star-Spangled Banner" echoed over Boylston Street, where the explosions rang out a year ago.
"I came as a refugee, and the United States gave me hope," said Keflezighi, who wrote the names of the three dead on his bib along with that of the MIT police officer who was killed during the manhunt that paralyzed Boston.
Later in the day Monday, at 2:49 p.m., the time the bombs went off, a moment of silence was observed at the finish line. It was followed by some of the loudest cheers of the day as people whooped, clapped and rang cowbells.
"Boston Strong" -- the unofficial slogan adopted after the terrorist attack -- was everywhere as the second-largest field of runners in the 118-year history of the race took part. Many of them were runners who had to abandon the race last year because of the attack.
"Today, when I got to that point, I said, ‘I have to do some unfinished business,"' said runner Vicki Schmidt, 52, of Nashville. She added: "You can't hold us back. You can't get us down. Boston is magical. This is our place."
While Gov. Deval Patrick said there had been no specific threats against the race or the city, police along the route examined backpacks, and runners had to use clear plastic bags for their belongings. More than 100 cameras were installed along the course in Boston, officials said.
Runner Scott Weisberg, 44, from Birmingham, Ala., said he had trouble sleeping the night before.
"With everything that happened last year, I can't stop worrying about it happening again. I know the chances are slim to none, but I can't help having a nervous pit in my stomach," Weisberg said.
Race organizers expanded the field from its recent cap of 27,000 to make room for more than 5,000 runners who were still on the course last year at the time of the explosions, for friends and relatives of the victims, and for those who were "profoundly impacted" by the attack.
Kenya's Rita Jeptoo won the women's race in a course-record 2 hours, 18 minutes, 57 seconds, defending the title she won last year.
Keflizighi won the men's title in 2 hours, 8 minutes, 37 seconds.
On Twitter, President Barack Obama congratulated Keflizighi and Shalane Flanagan, the top American finisher among the women, "for making American proud!"
"All of today's runners showed the world the meaning of #BostonStrong," Obama wrote.
Dzhokhar Tsarnaev, 20, is awaiting trial in the attack and could get the death penalty. Prosecutors said he and his older brother -- ethnic Chechens who came to the U.S. from Russia more than a decade ago -- carried out the attack in retaliation for U.S. wars in Muslim lands.
Tamerlan Tsarnaev, 26, died in a shootout with police days after the bombings.
Associated Press Writers Rik Stevens, Philip Marcelo, Michelle R. Smith, Bob Salsberg, Denise Lavoie, Steve Peoples, Paige Sutherland, freelancer Ken Powtak and AP Sports Writers Howard Ulman and Pat Eaton-Robb contributed to this story.