Dennis Kimetto of Kenya won the male division with an unofficial time of 2:03:45, breaking the previous record set last year of 2:04:38.
The winners of the wheelchair division finished the race in less than 2 hours. As a group of wheelchairs crossed the finish line a number of volunteers clapped and cheered.
Ernst Van Dyk of South Africa won the male wheelchair division with a time of 1:30:37 and the winner of the female wheelchair division, Tatyana McFadden of Champaign won with a time of 1:42:37.
As the runners raced along State Street, police officers in bright yellow vests kept watch at every intersection, lending a sense of reassurance to many in the crowd for the 36th annual race.
"You always think about safety because you never expect (violence), but I haven't felt uncomfortable at all," said Belinda Musgrave, who had come from Houston, Texas to cheer on her friend, Rhonda Kersgieter. "They seem to have everything under control."
Among the people at the end are a number of uniformed Chicago police officers who were standing guard behind the fence along side the finish line area.
A few of the uniformed officers were wearing bulletproof vests that read, "Department of Homeland Security POLICE" walked through that area. They were flanked by a homeland security K9 officer who was walking a bomb-sniffing dog.
The dog, appearing to be some sort of shepherd breed, wore a patch on its shoulder that read, "DO NOT PET."
Chicago Police officers are posted at nearly every intersection downtown as the city heightened security measures.
It was the bombing during the Boston Marathon earlier this year that inspired Marcy Wrzesinski to stand outside her apartment building on Sunday to cheer on the runners as they passed mile four in the Old Town neighborhood.
"The Boston Marathon I think freaked people out," Wrzesinski said.
A 10-year resident of Chicago, Sunday was the first time Wrzesinski made it out to watch the race.
"I normally watch from my bedroom window," she said. "I didn't want to shy away from it this year. I wanted to come out and give my support. Go America."
Wrzesinski and her husband Chet said they had noticed no extra security measures this year, except that the newspaper boxes in their neighborhood had disappeared.
At the corner of Jackson Boulevard and Halsted Street in Greek Town, Maxines Jones, 54, of Country Club Hills was waiting for about 15 friends to come running by. Jones said she has run the race three times before but this time she would be cheering the runners on.
"I've filled my bucket list," she said.
Jones, who works for the Cook County circuit court system, had salted-lime wedges ready for the runners because it helps runners with cramps, she said.
Jones said the crowd barriers were tighter this year. The increased security meant she would not be able to run a supportive stretch with her friends, Jones said.
"That was a big help," Jones said of her experience as a marathoner.
"It wasn't so secured," Jones said of the crowd barriers in years before the Boston Marathon bombing. "You can't run out and say hi."
"It wasn't all that strict" in past years, Jones said. "I understand it, but it puts a damper on the whole process."
"You can't go out there," Jones said laughing. "You'll get arrested!"
Jones said she especially liked having friends run alongside her on the final stretch, "Those 6.2 miles are the roughest."
Kathy Phalin, 51, of the Edison Park neighborhood, was also on hand in Greektown to cheer on her 30-year-old son, Ralph, who was running the marathon for the first time.
"We dropped him off at 5:30," said Phalin, an insurance agent.
Phalin said she wanted to come out and show her support for her son and all the runners
Hundreds of runners waited in line to use port-a-potties on the other side of the fountain. Two other watchtowers with two police officers each were also on the west and south ends of the fountain.
Mark Murphy, 60, is running in his first marathon. He's been a runner for 30 years, but he's only run in a series of shorter races in the Quad Cities area where he's from.
"You should be doing these in your 20s and 30s," Murphy, of Atkinson, joked before the race. "We'll see if I repeat after that."
Matt Grossman, 28, snapped a few photos of the skyline over Buckingham Fountain while other runners sat on either side of him getting in some pre-race stretching.
This is also his first marathon. He's been a runner for only about two years, but like Murphy, he has competed in shorter races.
Only Grossman is running with tendinitis in his right knee, the result of his rigorous training for the race.
"I'm going to give it a shot. We'll see what happens," said Grossman, of Grand Rapids, Mich.
Others said they felt the extra security presence.
"I can spot all the undercovers," said Sandy Thompson, 72, who came from Orlando, Fla. to cheer on her daughter, who ran the race.
Thompson, who works in security at Disney World, said she had no concerns about safety during the race.
"You can't be scared," she said. "And I think if something did happen, they would pick a different venue."
It was her 49-year-old daughter's final narathon, Thompson said as she rang a set of red cowbells and looked on into the rush of runners.
"I don't know what wave she's in so I just keep ringing these things," she said. "I know my arms are going to hurt tomorrow."
The Armstrong family were all in costume at the corner of halsted and w jackson because it was their 3-year-old daughter Gwendolyn's birthday and the party was after the race.
Gwendolyn's father, Duff Armstrong, 34, said security seemed a bit tighter but nothing too outlandish. Both Armstrong and his wife Megan said they've run the race in past years
"It's not noticeably a lot different," said Duff Armstrong, who was decked out as cat in the hat and holding his 1-year-old son, Paul who was dressed as spiderman. "But there seems to be more security in front of the runners."
Robb Lucas, 41, is running in his third marathon, all of which have been in Chicago. He said this race will be a great opportunity to learn from mistakes he made in the other two, like starting too fast or tying his shoelaces too tight so he doesn't hurt his toes.
Lucas said he's run in many races and hopes to compete in the Naperville half-marathon in November. But he believes today's race will likely sideline him for a week.
Shawn Maxwell, 36, meanwhile, is competing in his first marathon.
"This is my first one, so I'm gonna make all my mistakes today," said Maxwell, of North Aurora.
His added bonus for finishing the race?
"There's beer at the end."
A few uniformed officers stood by as a large wave of runners crossed mile four at LaSalle Drive and North Avenue at around 8 a.m.
Neighborhood residents said they'd noticed no new security compared to years past except that newspaper boxes had been removed before the race.
About 30 minutes before race time, a few dozen runners urinated in some bushes across from Buckingham Fountain. It would likely be the last time they'd be able to make a pit stop for the next several hours.
Hundreds of other runners waited in line to use port-a-potties on the other side of the fountain
Meanwhile, thousands of other runners scampered to the "gear check" tent so they could drop off their belongings. They were only allowed to carry them into the Marathon grounds in clear plastic bags.
Uniformed cops stood guard on two watchtowers (two officers on each) on the north and east ends of Buckingham Fountain to monitor all the foot traffic through the Marathon grounds. There were two other watchtowers with two cops a piece also on the west and south ends of the fountain.
They walked swiftly to the start line with spare bottles of water, Gatorade and other energy drinks.
Others like Mike DeRusso and Amanda McKenzie, both 24 and of Chicago, had energy gels taped to their arms. DeRusso said he plans on sucking on the gels ever 30 minutes to maintain his energy level for the 26.2-mile race.
This is DeRusso's second marathon--he ran the Pittsburgh Marathon in 2011. It's McKenzie's first marathon.
At 5 a.m., a few dozen security guards from Monterrey Security began checking people into the Marathon grounds along the Jackson Boulevard bridge, just east of the course along Columbus Drive.
The guards searched bags at several tables set up in the middle of the bridge. A large sign affixed to the checkpoint detailed a list of items forbidden on the Marathon grounds:
*large backpacks
*suitcases and rolling bags
*costumes covering the face or any non-formfitting bulky outfits extending beyond the perimeter if the body
*props and non-running equipment
*bicycles
*pets/animals (except for service animals)
A few dozen volunteers were already scattered along Columbus between the start and finish lines, and about 40 uniformed Chicago police officers also walked around sporting neon yellow vests.