The finish line is already crowded with spectators and police, with people squeezing through gaps in metal security barriers to get to their preferred watching spot.
Outside the Cactus Club, a restaurant on the corner of Fairfield and Boylston, were Betsy Wienslaw and Aubrey Cornforth, both 27, who watched the Marathon at the same spot last year. They thought about not coming back this year because of security concerns, but the checkpoints and barriers have made them feel safe today, and they decided it was important to show their support.
Plus, this is one of the only days this can get Sam Adams 26.2, a special marathon beer.
"It's one of the best days in Boston," Wienslaw said.
Amy Brakeman was among those fans lining the route. She remembers her father, George McDonald, qualifying for the Boston Marathon in 1979. That was when they were living in Palos Verdes, Calif.
Now, she lives in Wellesley, Mass. Her father, who is 80, lives in Long Beach, Calif., but they were both following the race today.
"I think of my dad each time I come out here to watch the marathon," Brakeman said, who got her dad on the phone for a joint interview.
Asked to remember the most enjoyable moment of that long-ago race (next to finishing, of course), McDonald did not hesitate. "The tunnel of screams," he said, referring to a stretch outside Wellesley college. "There was a huge mob of girls, screaming. It was the highlight."
McDonald went on to finish other marathons, but he never did Boston again.