"The Star-Spangled Banner" played over Boylston Street to honour American winner Meb Keflezighi, a special delight for many of the 35,000-plus runners who raced the Boston Marathon course Monday.

One year ago a bombing near the Boylston Street finish line killed three people and left more than 260 injured. Keflezighi, who previously won the New York City Marathon title in 2009 and a silver medal in the 2004 Olympics, kept the memory of last year's horror in his mind during the race.

Running just two weeks before his 39th birthday, he had the names of the 2013 bombing victims on his bib.

"At the end, I just kept thinking, 'Boston Strong. Boston Strong,"' he said. "I was thinking 'Give everything you have. If you get beat, that's it.'"

Keflezighi is the first American runner to win in Boston since Lisa Larsen-Weidenbach took the women's title in 1985.

But Monday’s race wasn’t just about the elite runners. Many athletes who were forced to stop short of the finish line last year came back to Boston to finish the race — arguably the most famous fixture on the running calendar.

"I showed up, I'm back, and I am going to finish what I didn't finish last year," said Mary Cunningham, 50, of St. Petersburg, Fla., who was stopped near a kilometre short of the finish line by the explosions on April 15, 2013.

Security was tight along the 42 kilometre course. Police were deployed in force along the route, with helicopters circling above and bomb-sniffing dogs checking through trash cans. Officers were also posted on roofs along the route.

Boston Marathon race director Dave McGillivray said it had been a long and difficult year.

"We're taking back our race," he said. "We're taking back the finish line."

A total of 35,755 athletes were registered to run — the second-largest field in its history, with many coming to show support for the event and the city that was traumatized by the attack on its signature sporting event.

'I showed up. I'm back, and I'm going to finish what I didn't finish last year.'- Mary Cunningham, 50, of St. Petersburg, Fla., who was stopped near a kilometre short of the finish line by the explosions last year.

Buses bearing the message "Boston Strong" dropped off runners at the starting line in the town of Hopkinton. A banner on one building read: "You are Boston Strong. You Earned This."

Among the signs lining the end of the route was one paying tribute to 8-year-old Martin Richard, the youngest of those killed in the bombing.

"No more hurting people. Peace," read the sign. A photograph of Martin holding a poster he made for school with those words was published after his death.

'I feel very safe'

Among the spectators cheering runners near the finish line was Jeff Bauman, who lost his legs in the bombing. It was the first time he had returned to the area since the attack.

"It feels great" to be back, he said. "I feel very safe."

Joe Ebert, 61, of Hampton, N.H., was cheering on his son-in-law near the spot in downtown Boston where the bombs went off. He was in the same area last year at the time of the attack.

Boston Marathon

Race fans cheer near the finish line at the 118th Boston Marathon on Monday. The race began with a moment of silence for those killed and injured in the bombing attacks during the event a year ago. (The Associated Press)

"I wanted to be in this spot," said Ebert, who wore a jacket and medal from when he ran the race in 2010. "Just wanted to let them know that they can't beat us down. I think it makes us all stronger when something like that happens."

Sabrina Dello Russo, 38, of South Boston, was running her first marathon for a good friend, Roseann Sdoia, who lost her right leg in the bombing.

"She is my inspiration from day one last year when I saw her in the ICU. Every run I do, she is in the back of my head, and she will be keeping me going today," Dello Russo said.

While Massachusetts Gov. Deval Patrick said there had been no specific threats against the race or the city, spectators at the 118th running of the world's oldest annual marathon had to go through tight checkpoints before being allowed near the starting and finish lines.

Fans hoping to watch near the finish line were encouraged to leave strollers and backpacks behind. Police set up checkpoints along the marathon route to examine backpacks, particularly outside subway station exits. And runners had to use clear plastic bags for their belongings.

More than 100 cameras installed

More than 100 cameras were installed along the route in Boston, and race organizers said 50 or so observation points would be set up around the finish line to monitor the crowd.

USA-BOSTON/MARATHON

About 36,000 runners are registered to run this year's Boston Marathon - one year after two bombs killed 3 people and wounded more than 260 others at the annual race. (Brian Snyder/Reuters)

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 made the case that they 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 a championship from last year. 

American Meb Keflizighi, a former New York City Marathon champion and Olympic medalist, won the men's title in 2 hours, 8 minutes, 37 seconds. Cheers rose up as word of the first American man to win in Boston since 1983 spread through the pack of runners.

Keflizighi had the names of last year's victims written in black marker on the corners of his race bib.

Other runners were expected to remain on the course for several hours after the winners crossed the finish line. Last year, the bombs went off at 2:49 p.m., as spectators crowded around the finish the line to cheer the still-arriving runners about five hours into the race.

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.